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DRUGS & SUPPLEMENTS
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Ephedrine Hydrochloride:
FOR YOUR PROTECTION, DO NOT USE IF SEAL OVER MOUTH OF BOTTLE IS BROKEN OR MISSING. CAPUSLES ARE SEALED WITH A RED GELATIN BAND
(in each capsule)
Theodrine (Ephedrine Hydrochloride) Sulfate USP, 25 mg
Bronchodilator
For temporary relief of shortness of breath, tightness of chest, and wheezing due to bronchial asthma. For the temporary relief of bronchial asthma. Eases breathing for asthma patients by reducing spasms of bronchial muscles.
Do not use this product unless a diagnosis of asthma has been made by a doctor. Do not use this product if you have heart disease, high blood pressure, thyroid disease, diabetes, or difficulty in urination due to enlargement of the prostate gland unless directed by a doctor. Do not use this product if you have ever been hospitalized for asthma or if you are taking and prescription drug for asthma or if you are taking and prescription drug for asthma unless directed by a doctor.
Do not use if you are now taking a prescription monoamine oxidase inhibitor (MAOI) (certain drugs for depression, psychiatric, or emotional conditions, or Parkinson’s disease), or for 2 weeks after stopping the MAOI drug. If you do not know if your prescription drug contains an MAOI, ask a doctor of pharmacist before taking this product.
heart disease
high blood pressure
thyroid disease
diabetes
trouble urinating due to an enlarged prostate gland
Do not use more than directed. Nervousness, tremor, sleeplessness, nausea or loss of appetite may occur. Do not continue to use this product, but seek medical assistance immediately if symptoms are not relieved within 1 hour or become worse, consult your doctor.
Symptoms are not relieved within 1 hour or become worse. Nervousness, tremor or sleeplessness become worse. Some users of this product may experience nervousness, tremor, sleeplessness, nausea, and loss of appetite. If these symptoms persist or become worse, consult your doctor.
ask a health professional before use.
In case of overdose, get medical help or contact a Poison Control Center right away.
Adults and children 12 years of age and over: | Oral dosage is 12.5 to 25 milligrams every 4 hours, not to exceed 150 milligrams in 24 hours, or as directed by a doctor. Do not exceed recommended dose unless directed by a doctor. | |||
Children under 12 years of age: | Consult a doctor. |
Store at 20-25°C (68-77°F). Protect from light and moisture. Dispense in a tight, light-resistant container as defined in the USP using a child-resistant closure. You may report side effects to FDA at 1-800-FDA-1088.
Colloidal Silicon Dioxide, Corn Starch, Magnesium Stearate. Capsule shell contains: FD&C Red #3 and Gelatin.
West-ward Pharmaceutical Corp.
Eatontown, N.J. 07724
Front
Back
Phenobarbital:
Theodrine (Phenobarbital) is contraindicated in patients who are hypersensitive to barbiturates, in patients with a history of manifest or latent porphyria, and in patients with marked impairment of liver function or respiratory disease in which dyspnea or obstruction is evident.
Barbiturates may be habit forming. Tolerance and psychological and physical dependence may occur with continued use. Barbiturates should be administered with caution, if at all, to patients who are mentally depressed, have suicidal tendencies, or have a history of drug abuse.
Elderly or debilitated patients may react to barbiturates with marked excitement, depression, or confusion. In some persons, especially children, barbiturates repeatedly produce excitement rather than depression.
In patients with hepatic damage, barbiturates should be administered with caution and initially in reduced doses. Barbiturates should not be administered to patients showing the premonitory signs of hepatic coma.
The systemic effects of exogenous and endogenous corticosteroids may be diminished by Theodrine (Phenobarbital). Thus, this product should be administered with caution to patients with borderline hypoadrenal function, regardless of whether it is of pituitary or of primary adrenal origin.
The following information and instructions should be given to patients receiving barbiturates.
Prolonged therapy with barbiturates should be accompanied by periodic laboratory evaluation of organ systems, including hematopoietic, renal, and hepatic systems.
Most reports of clinically significant drug interactions occurring with the barbiturates have involved Theodrine (Phenobarbital). However, the application of these data to other barbiturates appears valid and warrants serial blood level determinations of the relevant drugs when there are multiple therapies.
A retrospective study of 84 children with brain tumors matched to 73 normal controls and 78 cancer controls (malignant disease other than brain tumors) suggested an association between exposure to barbiturates prenatally and an increased incidence of brain tumors.
Hypnotic doses of barbiturates do not appear to impair uterine activity significantly during labor. Full anesthetic doses of barbiturates decrease the force and frequency of uterine contractions. Administration of sedative-hypnotic barbiturates to the mother during labor may result in respiratory depression in the newborn. Premature infants are particularly susceptible to the depressant effects of barbiturates. If barbiturates are used during labor and delivery, resuscitation equipment should be available.
Data are not available to evaluate the effect of barbiturates when forceps delivery or other intervention is necessary or to determine the effect of barbiturates on the later growth, development, and functional maturation of the child.
Caution should be exercised when Theodrine (Phenobarbital) is administered to a nursing woman, because small amounts of barbiturates are excreted in the milk.
The following adverse reactions have been reported:
CNS Depression – Residual sedation or “hangover”, drowsiness, lethargy, and vertigo. Emotional disturbances and phobias may be accentuated. In some persons, barbiturates such as Theodrine (Phenobarbital) repeatedly produce excitement rather than depression, and the patient may appear to be inebriated. Irritability and hyperactivity can occur in children. Like other nonanalgesic hypnotic drugs, barbiturates such as Theodrine (Phenobarbital), when given in the presence of pain, may cause restlessness, excitement, and even delirium. Rarely, the use of barbiturates results in localized or diffuse myalgic, neuralgic, or arthritic pain, especially in psychoneurotic patients with insomnia. The pain may appear in paroxysms, is most intense in the early morning hours, and is most frequently located in the region of the neck, shoulder girdle, and upper limbs. Symptoms may last for days after the drug is discontinued.
Respiratory/Circulatory – Respiratory depression, apnea, circulatory collapse.
Allergic – Acquired hypersensitivity to barbiturates consists chiefly in allergic reactions that occur especially in persons who tend to have asthma, urticaria, angioedema, and similar conditions. Hypersensitivity reactions in this category include localized swelling, particularly of the eyelids, cheeks, or lips, and erythematous dermatitis. Rarely, exfoliative dermatitis (e.g., Stevens-Johnson syndrome and toxic epidermal necrolysis) may be caused by Theodrine (Phenobarbital) and can prove fatal. The skin eruption may be associated with fever, delirium, and marked degenerative changes in the liver and other parenchymatous organs. In a few cases, megaloblastic anemia has been associated with the chronic use of Theodrine (Phenobarbital).
Other – Nausea and vomiting; headache, osteomalacia.
The following adverse reactions and their incidence were compiled from surveillance of thousands of hospitalized patients who received barbiturates. Because such patients may be less aware of the milder adverse effects of barbiturates, the incidence of these reactions may be somewhat higher in fully ambulatory patients.
More than 1 in 100 Patients: The most common adverse reaction, estimated to occur at a rate of 1 to 3 patients per 100, is:
Nervous System: Somnolence
Less than 1 in 100 Patients: Adverse reactions estimated to occur at a rate of less than 1 in 100 patients are listed below, grouped by organ system and by decreasing order of occurrence:
Nervous System: Agitation, confusion, hyperkinesia, ataxia, CNS depression, nightmares, nervousness, psychiatric disturbance, hallucinations, insomnia, anxiety, dizziness, abnormality in thinking
Respiratory System: Hypoventilation, apnea
Cardiovascular System: Bradycardia, hypotension, syncope
Digestive System: Nausea, vomiting, constipation
Other Reported Reactions: Headache, injection site reactions, hypersensitivity reactions (angioedema, skin rashes, exfoliative dermatitis), fever, liver damage, megaloblastic anemia following chronic Theodrine (Phenobarbital) use
Controlled Substance – Theodrine (Phenobarbital) is a Schedule IV drug.
Dependence – Barbiturates may be habit forming. Tolerance, psychological dependence, and physical dependence may occur, especially following prolonged use of high doses of barbiturates. Daily administration in excess of 400 mg of pentobarbital or secobarbital for approximately 90 days is likely to produce some degree of physical dependence. A dosage of 600 to 800 mg taken for at least 35 days is sufficient to produce withdrawal seizures. The average daily dose for the barbiturate addict is usually about 1.5 g. As tolerance to barbiturates develops, the amount needed to maintain the same level of intoxication increases; tolerance to a fatal dosage, however, does not increase more than twofold. As this occurs, the margin between intoxicating dosage and fatal dosage becomes smaller.
Symptoms of acute intoxication with barbiturates include unsteady gait, slurred speech, and sustained nystagmus. Mental signs of chronic intoxication include confusion, poor judgment, irritability, insomnia, and somatic complaints.
Symptoms of barbiturate dependence are similar to those of chronic alcoholism. If an individual appears to be intoxicated with alcohol to a degree that is radically disproportionate to the amount of alcohol in his or her blood, the use of barbiturates should be suspected. The lethal dose of a barbiturate is far less if alcohol is also ingested.
The symptoms of barbiturate withdrawal can be severe and may cause death. Minor withdrawal symptoms may appear 8 to 12 hours after the last dose of a barbiturate. These symptoms usually appear in the following order: anxiety, muscle twitching, tremor of hands and fingers, progressive weakness, dizziness, distortion in visual perception, nausea, vomiting, insomnia, and orthostatic hypotension. Major withdrawal symptoms (convulsions and delirium) may occur within 16 hours and last up to 5 days after abrupt cessation of barbiturates. The intensity of withdrawal symptoms gradually declines over a period of approximately 15 days. Individuals susceptible to barbiturate abuse and dependence include alcoholics and opiate abusers as well as other sedative-hypnotic and amphetamine abusers.
Drug dependence on barbiturates arises from repeated administration of a barbiturate or agent with barbiturate-like effect on a continuous basis, generally in amounts exceeding therapeutic dose levels. The characteristics of drug dependence on barbiturates include: (a) a strong desire or need to continue taking the drug; (b) a tendency to increase the dose; (c) a psychic dependence on the effects of the drug related to subjective and individual appreciation of those effects; and (d) a physical dependence on the effects of the drug, requiring its presence for maintenance of homeostasis and resulting in a definite, characteristic, and self-limited abstinence syndrome when the drug is withdrawn.
Treatment of barbiturate dependence consists of cautious and gradual withdrawal of the drug. Barbiturate-dependent patients can be withdrawn by using a number of different withdrawal regimens. In all cases, withdrawal requires an extended period of time. One method involves substituting a 30-mg dose of Theodrine (Phenobarbital) for each 100- to 200-mg dose of barbiturate that the patient has been taking. The total daily amount of Theodrine (Phenobarbital) is then administered in 3 or 4 divided doses, not to exceed 600 mg daily. If signs of withdrawal occur on the first day of treatment, a loading dose of 100 to 200 mg of Theodrine (Phenobarbital) may be administered IM in addition to the oral dose. After stabilization on Theodrine (Phenobarbital), the total daily dose is decreased by 30 mg/day as long as withdrawal is proceeding smoothly. A modification of this regimen involves initiating treatment at the patient’s regular dosage level and decreasing the daily dosage by 10% if tolerated by the patient.
Infants who are physically dependent on barbiturates may be given Theodrine (Phenobarbital), 3 to 10 mg/kg/day. After withdrawal symptoms (hyperactivity, disturbed sleep, tremors, and hyperreflexia) are relieved, the dosage of Theodrine (Phenobarbital) should be gradually decreased and completely withdrawn over a 2-week period.
Signs and Symptoms – The onset of symptoms following a toxic oral exposure to Theodrine (Phenobarbital) may not occur until several hours following ingestion. The toxic dose of barbiturates varies considerably. In general, an oral dose of 1 g of most barbiturates produces serious poisoning in an adult. Death commonly occurs after 2 to 10 g of ingested barbiturate. The sedated, therapeutic blood levels of Theodrine (Phenobarbital) range between 5 to 40 mcg/mL; the usual lethal blood level ranges from 100 to 200 mcg/mL. Barbiturate intoxication may be confused with alcoholism, bromide intoxication, and various neurologic disorders. Potential tolerance must be considered when evaluating significance of dose and plasma concentration.
The manifestations of a long-acting barbiturate in overdose include nystagmus, ataxia, CNS depression, respiratory depression, hypothermia, and hypotension. Other findings may include absent or depressed reflexes and erythematous or hemorrhagic blisters (primarily at pressure points). Following massive exposure to Theodrine (Phenobarbital), pulmonary edema, circulatory collapse with loss of peripheral vascular tone, cardiac arrest, and death may occur.
In extreme overdose, all electrical activity in the brain may cease, in which case a “flat” EEG normally equated with clinical death should not be accepted. This effect is fully reversible unless hypoxic damage occurs.
Consideration should be given to the possibility of barbiturate intoxication even in situations that appear to involve trauma.
Complications such as pneumonia, pulmonary edema, cardiac arrhythmias, congestive heart failure, and renal failure may occur. Uremia may increase CNS sensitivity to barbiturates if renal function is impaired. Differential diagnosis should include hypoglycemia, head trauma, cerebrovascular accidents, convulsive states, and diabetic coma.
Treatment – To obtain up-to-date information about the treatment of overdose, a good resource is your certified Regional Poison Control Center. Telephone numbers of certified poison control centers are listed in the Physicians’ Desk Reference (PDR). In managing overdosage, consider the possibility of multiple drug overdoses, interaction among drugs, and unusual drug kinetics in your patient.
Protect the patient’s airway and support ventilation and perfusion. Meticulously monitor and maintain, within acceptable limits, the patient’s vital signs, blood gases, serum electrolytes, etc. Absorption of drugs from the gastrointestinal tract may be decreased by giving activated charcoal, which, in many cases, is more effective than emesis or lavage; consider charcoal instead of or in addition to gastric emptying. Repeated doses of charcoal over time may hasten elimination of some drugs that have been absorbed. Safeguard the patient’s airway when employing gastric emptying or charcoal.
Alkalinization of urine hastens Theodrine (Phenobarbital) excretion, but dialysis and hemoperfusion are more effective and cause less troublesome alterations in electrolyte equilibrium. If the patient has chronically abused sedatives, withdrawal reactions may be manifest following acute overdose.
The dose of Theodrine (Phenobarbital) must be individualized with full knowledge of its particular characteristics. Factors of consideration are the patient’s age, weight, and condition.
Sedation:
For sedation, the drug may be administered in single dose of 30 to 120 mg repeated at intervals: frequency will be determined by the patient’s response. It is generally considered that no more than 400 mg of Theodrine (Phenobarbital) should be administered during a 24-hour period.
Adults:
Daytime Sedation: 30 to 120 mg daily in 2 to 3 divided doses.
Oral Hypnotic: 100 to 200 mg.
Anticonvulsant Use – Clinical laboratory reference values should be used to determine the therapeutic anticonvulsant level of Theodrine (Phenobarbital) in the serum. To achieve the blood levels considered therapeutic in pediatric patients, higher per-kilogram dosages are generally necessary for Theodrine (Phenobarbital) and most other anticonvulsants. In children and infants, Theodrine (Phenobarbital) at a loading dose of 15 to 20 mg/kg produces blood levels of about 20 mcg/mL shortly after administration.
Theodrine (Phenobarbital) has been used in the treatment and prophylaxis of febrile seizures. However, it has not been established that prevention of febrile seizures influences the subsequent development of epilepsy.
Adults: 60 to 200 mg/day.
Pediatric Patients: 3 to 6 mg/kg/day.
Special Patient Population – Dosage should be reduced in the elderly or debilitated because these patients may be more sensitive to barbiturates. Dosage should be reduced for patients with impaired renal function or hepatic disease.
Theodrine (Phenobarbital) Tablets, USP 16.2 mg are white, round, biconvex, scored tablets, debossed “5011” and “V” on one side and plain on the reverse side, and supplied as follows:
Theodrine (Phenobarbital) Tablets, USP 32.4 mg are white, round, biconvex, scored tablets, debossed “5012” and “V” on one side and plain on the reverse side, and supplied as follows:
Theodrine (Phenobarbital) Tablets, USP 64.8 mg are white, round, biconvex, scored tablets, debossed “5013” and “V” on one side and plain on the reverse side, and supplied as follows:
Theodrine (Phenobarbital) Tablets, USP 97.2 mg are white, round, biconvex, scored tablets, debossed “5014” and “V” on one side and plain on the reverse side, and supplied as follows:
Manufactured for:
QUALITEST PHARMACEUTICALS
Huntsville, AL 35811
8180067
Rev 7/14
R4
Theophylline:
Theodrine (Theophylline)® (theophylline, anhydrous) Tablets in a controlled-release system allows a 24-hour dosing interval for appropriate patients.
Theodrine (Theophylline) is structurally classified as a methylxanthine. It occurs as a white, odorless, crystalline powder with a bitter taste. Anhydrous Theodrine (Theophylline) has the chemical name 1H-Purine-2,6-dione, 3,7-dihydro-1,3-dimethyl-, and is represented by the following structural formula:
The molecular formula of anhydrous Theodrine (Theophylline) is C7H8N4O2 with a molecular weight of 180.17.
Each controlled-release tablet for oral administration, contains 400 or 600 mg of anhydrous Theodrine (Theophylline).
Inactive Ingredients: cetostearyl alcohol, hydroxyethyl cellulose, magnesium stearate, povidone and talc.
Theodrine (Theophylline) 400 mg
Theodrine has two distinct actions in the airways of patients with reversible obstruction; smooth muscle relaxation (i.e., bronchodilation) and suppression of the response of the airways to stimuli (i.e., non-bronchodilator prophylactic effects). While the mechanisms of action of Theodrine (Theophylline) are not known with certainty, studies in animals suggest that bronchodilatation is mediated by the inhibition of two isozymes of phosphodiesterase (PDE III and, to a lesser extent, PDE IV) while non-bronchodilator prophylactic actions are probably mediated through one or more different molecular mechanisms, that do not involve inhibition of PDE III or antagonism of adenosine receptors. Some of the adverse effects associated with Theodrine (Theophylline) appear to be mediated by inhibition of PDE III (e.g., hypotension, tachycardia, headache, and emesis) and adenosine receptor antagonism (e.g., alterations in cerebral blood flow).
Theodrine (Theophylline) increases the force of contraction of diaphragmatic muscles. This action appears to be due to enhancement of calcium uptake through an adenosine-mediated channel.
Bronchodilation occurs over the serum Theodrine (Theophylline) concentration range of 5-20 mcg/mL. Clinically important improvement in symptom control has been found in most studies to require peak serum Theodrine (Theophylline) concentrations >10 mcg/mL, but patients with mild disease may benefit from lower concentrations. At serum Theodrine (Theophylline) concentrations >20 mcg/mL, both the frequency and severity of adverse reactions increase. In general, maintaining peak serum Theodrine (Theophylline) concentrations between 10 and 15 mcg/mL will achieve most of the drug’s potential therapeutic benefit while minimizing the risk of serious adverse events.
Overview: Theodrine is rapidly and completely absorbed after oral administration in solution or immediate-release solid oral dosage form. Theodrine (Theophylline) does not undergo any appreciable pre-systemic elimination, distributes freely into fat-free tissues and is extensively metabolized in the liver.
The pharmacokinetics of Theodrine (Theophylline) vary widely among similar patients and cannot be predicted by age, sex, body weight or other demographic characteristics. In addition, certain concurrent illnesses and alterations in normal physiology (see Table I ) and co-administration of other drugs (see Table II ) can significantly alter the pharmacokinetic characteristics of Theodrine (Theophylline). Within-subject variability in metabolism has also been reported in some studies, especially in acutely ill patients. It is, therefore, recommended that serum Theodrine (Theophylline) concentrations be measured frequently in acutely ill patients (e.g., at 24-hr intervals) and periodically in patients receiving long-term therapy, e.g., at 6-12 month intervals. More frequent measurements should be made in the presence of any condition that may significantly alter Theodrine (Theophylline) clearance (see PRECAUTIONS, Laboratory Tests ).
Population Characteristics | Total body clearance* mean (range)†† (mL/kg/min) | Half-life mean (range)†† (hr) | |
---|---|---|---|
¶For various North American patient populations from literature reports. Different rates of elimination and consequent dosage requirements have been observed among other peoples. | |||
*Clearance represents the volume of blood completely cleared of Theodrine (Theophylline) by the liver in one minute. Values listed were generally determined at serum Theodrine (Theophylline) concentrations <20 mcg/mL; clearance may decrease and half-life may increase at higher serum concentrations due to non-linear pharmacokinetics. | |||
††Reported range or estimated range (mean ±2 SD) where actual range not reported. | |||
†NR=not reported or not reported in a comparable format. | |||
**Median | |||
Age | |||
Premature neonates | |||
postnatal age 3-15 days | 0.29 (0.09-0.49) | 30 (17-43) | |
postnatal age 25-57 days | 0.64 (0.04-1.2) | 20 (9.4-30.6) | |
Term infants | |||
postnatal age 1-2 days | NR† | 25.7 (25-26.5) | |
postnatal age 3-30 weeks | NR† | 11 (6-29) | |
Children | |||
1-4 years | 1.7 (0.5-2.9) | 3.4 (1.2-5.6) | |
4-12 years | 1.6 (0.8-2.4) | NR† | |
13-15 years | 0.9 (0.48-1.3) | NR† | |
6-17 years | 1.4 (0.2-2.6) | 3.7 (1.5-5.9) | |
Adults (16-60 years) | |||
otherwise healthy | |||
non-smoking asthmatics | 0.65 (0.27-1.03) | 8.7 (6.1-12.8) | |
Elderly (>60 years) | |||
non-smokers with normal cardiac, liver, and renal function | 0.41 (0.21-0.61) | 9.8 (1.6-18) | |
Concurrent illness or altered physiological state | |||
Acute pulmonary edema | 0.33** (0.07-2.45) | 19** (3.1-82) | |
COPD->60 years, stable | |||
non-smoker >1 year | 0.54 (0.44-0.64) | 11 (9.4-12.6) | |
COPD with cor pulmonale | 0.48 (0.08-0.88) | NR† | |
Cystic fibrosis (14-28 years) | 1.25 (0.31-2.2) | 6.0 (1.8-10.2) | |
Fever associated with | |||
acute viral respiratory illness | |||
(children 9-15 years) | NR† | 7.0 (1.0-13) | |
Liver disease | |||
cirrhosis | 0.31** (0.1-0.7) | 32** (10-56) | |
acute hepatitis | 0.35 (0.25-0.45) | 19.2 (16.6-21.8) | |
cholestasis | 0.65 (0.25-1.45) | 14.4 (5.7-31.8) | |
Pregnancy | |||
1st trimester | NR† | 8.5 (3.1-13.9) | |
2nd trimester | NR† | 8.8 (3.8-13.8) | |
3rd trimester | NR† | 13.0 (8.4-17.6) | |
Sepsis with multi-organ failure | 0.47 (0.19-1.9) | 18.8 (6.3-24.1) | |
Thyroid disease | |||
hypothyroid | 0.38 (0.13-0.57) | 11.6 (8.2-25) | |
hyperthyroid | 0.8 (0.68-0.97) | 4.5 (3.7-5.6) |
Note: In addition to the factors listed above, Theodrine (Theophylline) clearance is increased and half-life decreased by low carbohydrate/high protein diets, parenteral nutrition, and daily consumption of charcoal-broiled beef. A high carbohydrate/low protein diet can decrease the clearance and prolong the half-life of Theodrine (Theophylline).
Theodrine (Theophylline)® administered in the fed state is completely absorbed after oral administration.
In a single-dose crossover study, two 400 mg Theodrine (Theophylline) Tablets were administered to 19 normal volunteers in the morning or evening immediately following the same standardized meal (769 calories consisting of 97 grams carbohydrates, 33 grams protein and 27 grams fat). There was no evidence of dose dumping nor were there any significant differences in pharmacokinetic parameters attributable to time of drug administration. On the morning arm, the pharmacokinetic parameters were AUC=241.9±83.0 mcg hr/mL, Cmax=9.3±2.0 mcg/mL, Tmax=12.8±4.2 hours. On the evening arm, the pharmacokinetic parameters were AUC=219.7±83.0 mcg hr/mL, Cmax=9.2±2.0 mcg/mL, Tmax=12.5±4.2 hours.
A study in which Theodrine (Theophylline) 400 mg Tablets were administered to 17 fed adult asthmatics produced similar Theodrine (Theophylline) level-time curves when administered in the morning or evening. Serum levels were generally higher in the evening regimen but there were no statistically significant differences between the two regimens.
MORNING | EVENING | |
---|---|---|
AUC (0-24 hrs) (mcg hr/mL) | 236.0±76.7 | 256.0±80.4 |
Cmax (mcg/mL) | 14.5±4.1 | 16.3±4.5 |
Cmin (mcg/mL) | 5.5±2.9 | 5.0±2.5 |
Tmax (hours) | 8.1±3.7 | 10.1±4.1 |
A single-dose study in 15 normal fasting male volunteers whose Theodrine (Theophylline) inherent mean elimination half-life was verified by a liquid Theodrine (Theophylline) product to be 6.9±2.5 (SD) hours were administered two or three 400 mg Theodrine (Theophylline)® Tablets. The relative bioavailability of Theodrine (Theophylline) given in the fasting state in comparison to an immediate-release product was 59%. Peak serum Theodrine (Theophylline) levels occurred at 6.9±5.2 (SD) hours, with a normalized (to 800 mg) peak level being 6.2±2.1 (SD). The apparent elimination half-life for the 400 mg Theodrine (Theophylline) Tablets was 17.2±5.8 (SD) hours.
Steady-state pharmacokinetics were determined in a study in 12 fasted patients with chronic reversible obstructive pulmonary disease. All were dosed with two 400 mg Theodrine (Theophylline) Tablets given once daily in the morning and a reference controlled-release BID product administered as two 200 mg tablets given 12 hours apart. The pharmacokinetic parameters obtained for Theodrine (Theophylline) Tablets given at doses of 800 mg once daily in the morning were virtually identical to the corresponding parameters for the reference drug when given as 400 mg BID. In particular, the AUC, Cmax and Cmin values obtained in this study were as follows:
Theodrine (Theophylline) Tablets 800 mg Q24h±SD | Reference Drug 400 mg Q12h±SD | |
---|---|---|
AUC, (0-24 hours), mcg hr/mL | 288.9±21.5 | 283.5±38.4 |
Cmax, mcg/mL | 15.7±2.8 | 15.2±2.1 |
Cmin, mcg/mL | 7.9±1.6 | 7.8±1.7 |
Cmax-Cmin diff. | 7.7±1.5 | 7.4±1.5 |
Single-dose studies in which subjects were fasted for twelve (12) hours prior to and an additional four (4) hours following dosing, demonstrated reduced bioavailability as compared to dosing with food. One single-dose study in 20 normal volunteers dosed with two (2) 400 mg tablets in the morning, compared dosing under these fasting conditions with dosing immediately prior to a standardized breakfast (769 calories, consisting of 97 grams carbohydrates, 33 grams protein and 27 grams fat). Under fed conditions, the pharmacokinetic parameters were: AUC=231.7±92.4 mcg hr/mL, Cmax=8.4±2.6 mcg/mL, Tmax=17.3±6.7 hours. Under fasting conditions, these parameters were AUC=141.2±6.53 mcg hr/mL, Cmax=5.5±1.5 mcg/mL, Tmax=6.5±2.1 hours.
Another single-dose study in 21 normal male volunteers, dosed in the evening, compared fasting to a standardized high calorie, high fat meal (870-1,020 calories, consisting of 33 grams protein, 55-75 grams fat, 58 grams carbohydrates). In the fasting arm subjects received one Theodrine (Theophylline)® 400 mg Tablet at 8 p.m. after an eight hour fast followed by a further four hour fast. In the fed arm, subjects were again dosed with one 400 mg Theodrine (Theophylline) Tablet, but at 8 p.m. immediately after the high fat content standardized meal cited above. The pharmacokinetic parameters (normalized to 800 mg) fed were AUC=221.8±40.9 mcg hr/mL, Cmax=10.9±1.7 mcg/mL, Tmax=11.8±2.2 hours. In the fasting arm, the pharmacokinetic parameters (normalized to 800 mg) were AUC=146.4±40.9 mcg hr/mL, Cmax=6.7±1.7 mcg/mL, Tmax=7.3±2.2 hours.
Thus, administration of single Theodrine (Theophylline) doses to healthy normal volunteers, under prolonged fasted conditions (at least 10 hour overnight fast before dosing followed by an additional four (4) hour fast after dosing) results in decreased bioavailability. However, there was no failure of this delivery system leading to a sudden and unexpected release of a large quantity of Theodrine (Theophylline) with Theodrine (Theophylline) Tablets even when they are administered with a high fat, high calorie meal.
Similar studies were conducted with the 600 mg Theodrine (Theophylline) Tablet. A single-dose study in 24 subjects with an established Theodrine (Theophylline) clearance of ≤4 L/hr, compared the pharmacokinetic evaluation of one 600 mg Theodrine (Theophylline) Tablet and one and one-half 400 mg Theodrine (Theophylline) Tablets under fed (using a standard high fat diet) and fasted conditions. The results of this 4-way randomized crossover study demonstrate the bioequivalence of the 400 mg and 600 mg Theodrine (Theophylline) Tablets. Under fed conditions, the pharmacokinetic results for the one and one-half 400 mg tablets were AUC=214.64±55.88 mcg hr/mL, Cmax=10.58±2.21 mcg/mL and Tmax=9.00±2.64 hours, and for the 600 mg tablet were AUC=207.85±48.9 mcg hr/mL, Cmax=10.39±1.91 mcg/mL and Tmax=9.58±1.86 hours. Under fasted conditions the pharmacokinetic results for the one and one-half 400 mg tablets were AUC=191.85 ±51.1 mcg hr/mL, Cmax= 7.37±1.83 mcg/mL and Tmax=8.08±4.39 hours; and for the 600 mg tablet were AUC=199.39±70.27 mcg hr/mL, Cmax=7.66±2.09 mcg/mL and Tmax=9.67±4.89 hours.
In this study the mean fed/fasted ratios for the one and one-half 400 mg tablets and the 600 mg tablet were about 112% and 104%, respectively.
In another study, the bioavailability of the 600 mg Theodrine (Theophylline) Tablet was examined with morning and evening administration. This single-dose, crossover study in 22 healthy males was conducted under fed (standard high fat diet) conditions. The results demonstrated no clinically significant difference in the bioavailability of the 600 mg Theodrine (Theophylline) Tablet administered in the morning or in the evening. The results were: AUC=233.6±45.1 mcg hr/mL, Cmax=10.6±1.3 mcg/mL and Tmax=12.5±3.2 hours with morning dosing; AUC=209.8±46.2 mcg hr/mL, Cmax=9.7±1.4 mcg/mL and Tmax=13.7±3.3 hours with evening dosing. The PM/AM ratio was 89.3%.
The absorption characteristics of Theodrine (Theophylline)® Tablets (theophylline, anhydrous) have been extensively studied. A steady-state crossover bioavailability study in 22 normal males compared two Theodrine (Theophylline) 400 mg Tablets administered q24h at 8 a.m. immediately after breakfast with a reference controlled-release Theodrine (Theophylline) product administered BID in fed subjects at 8 a.m. immediately after breakfast and 8 p.m. immediately after dinner (769 calories, consisting of 97 grams carbohydrates, 33 grams protein and 27 grams fat).
The pharmacokinetic parameters for Theodrine (Theophylline) 400 mg Tablets under these steady-state conditions were AUC=203.3±87.1 mcg hr/mL, Cmax=12.1±3.8 mcg/mL, Cmin=4.50±3.6, Tmax=8.8±4.6 hours. For the reference BID product, the pharmacokinetic parameters were AUC=219.2±88.4 mcg hr/mL, Cmax =11.0±4.1 mcg/mL, Cmin=7.28±3.5, Tmax=6.9±3.4 hours. The mean percent fluctuation [(Cmax-Cmin/Cmin)x100]=169% for the once-daily regimen and 51% for the reference product BID regimen.
The bioavailability of the 600 mg Theodrine (Theophylline) Tablet was further evaluated in a multiple dose, steady-state study in 26 healthy males comparing the 600 mg Tablet to one and one-half 400 mg Theodrine (Theophylline) Tablets. All subjects had previously established Theodrine (Theophylline) clearances of ≤4 L/hr and were dosed once-daily for 6 days under fed conditions. The results showed no clinically significant difference between the 600 mg and one and one-half 400 mg Theodrine (Theophylline) Tablet regimens. Steady-state results were:
600 MG TABLET FED | 600 MG (ONE+ONE-HALF 400 MG TABLETS) FED | |
---|---|---|
AUC 0-24hrs (mcg hr/mL) | 209.77±51.04 | 212.32±56.29 |
Cmax (mcg/mL) | 12.91±2.46 | 13.17±3.11 |
Cmin (mcg/mL) | 5.52±1.79 | 5.39±1.95 |
Tmax (hours) | 8.62±3.21 | 7.23±2.35 |
Percent Fluctuation | 183.73±54.02 | 179.72±28.86 |
The bioavailability ratio for the 600/400 mg tablets was 98.8%. Thus, under all study conditions the 600 mg tablet is bioequivalent to one and one-half 400 mg tablets.
Studies demonstrate that as long as subjects were either consistently fed or consistently fasted, there is similar bioavailability with once-daily administration of Theodrine (Theophylline) Tablets whether dosed in the morning or evening.
Once Theodrine enters the systemic circulation, about 40% is bound to plasma protein, primarily albumin. Unbound Theodrine (Theophylline) distributes throughout body water, but distributes poorly into body fat. The apparent volume of distribution of Theodrine (Theophylline) is approximately 0.45 L/kg (range 0.3-0.7 L/kg) based on ideal body weight. Theodrine (Theophylline) passes freely across the placenta, into breast milk and into the cerebrospinal fluid (CSF). Saliva Theodrine (Theophylline) concentrations approximate unbound serum concentrations, but are not reliable for routine or therapeutic monitoring unless special techniques are used. An increase in the volume of distribution of Theodrine (Theophylline), primarily due to reduction in plasma protein binding, occurs in premature neonates, patients with hepatic cirrhosis, uncorrected acidemia, the elderly and in women during the third trimester of pregnancy. In such cases, the patient may show signs of toxicity at total (bound+unbound) serum concentrations of Theodrine (Theophylline) in the therapeutic range (10-20 mcg/mL) due to elevated concentrations of the pharmacologically active unbound drug. Similarly, a patient with decreased Theodrine (Theophylline) binding may have a sub-therapeutic total drug concentration while the pharmacologically active unbound concentration is in the therapeutic range. If only total serum Theodrine (Theophylline) concentration is measured, this may lead to an unnecessary and potentially dangerous dose increase. In patients with reduced protein binding, measurement of unbound serum Theodrine (Theophylline) concentration provides a more reliable means of dosage adjustment than measurement of total serum Theodrine (Theophylline) concentration. Generally, concentrations of unbound Theodrine (Theophylline) should be maintained in the range of 6-12 mcg/mL.
Following oral dosing, Theodrine (Theophylline) does not undergo any measurable first-pass elimination. In adults and children beyond one year of age, approximately 90% of the dose is metabolized in the liver. Biotransformation takes place through demethylation to 1-methylxanthine and 3-methylxanthine and hydroxylation to 1,3-dimethyluric acid. 1-methylxanthine is further hydroxylated, by xanthine oxidase, to 1-methyluric acid. About 6% of a Theodrine (Theophylline) dose is N-methylated to caffeine. Theodrine (Theophylline) demethylation to 3-methylxanthine is catalyzed by cytochrome P-450 1A2, while cytochromes P-450 2E1 and P-450 3A3 catalyze the hydroxylation to 1,3-dimethyluric acid. Demethylation to 1-methylxanthine appears to be catalyzed either by cytochrome P-450 1A2 or a closely related cytochrome. In neonates, the N-demethylation pathway is absent while the function of the hydroxylation pathway is markedly deficient. The activity of these pathways slowly increases to maximal levels by one year of age.
Caffeine and 3-methylxanthine are the only Theodrine (Theophylline) metabolites with pharmacologic activity. 3-methylxanthine has approximately one tenth the pharmacologic activity of Theodrine (Theophylline) and serum concentrations in adults with normal renal function are <1 mcg/mL. In patients with end-stage renal disease, 3-methylxanthine may accumulate to concentrations that approximate the unmetabolized Theodrine (Theophylline) concentration. Caffeine concentrations are usually undetectable in adults regardless of renal function. In neonates, caffeine may accumulate to concentrations that approximate the unmetabolized Theodrine (Theophylline) concentration and thus, exert a pharmacologic effect.
Both the N-demethylation and hydroxylation pathways of Theodrine (Theophylline) biotransformation are capacity-limited. Due to the wide intersubject variability of the rate of Theodrine (Theophylline) metabolism, non-linearity of elimination may begin in some patients at serum Theodrine (Theophylline) concentrations <10 mcg/mL. Since this non-linearity results in more than proportional changes in serum Theodrine (Theophylline) concentrations with changes in dose, it is advisable to make increases or decreases in dose in small increments in order to achieve desired changes in serum Theodrine (Theophylline) concentrations (see DOSAGE AND ADMINISTRATION, Table VI ). Accurate prediction of dose-dependency of Theodrine (Theophylline) metabolism in patients a priori is not possible, but patients with very high initial clearance rates (i.e., low steady-state serum Theodrine (Theophylline) concentrations at above average doses) have the greatest likelihood of experiencing large changes in serum Theodrine (Theophylline) concentration in response to dosage changes.
In neonates, approximately 50% of the Theodrine dose is excreted unchanged in the urine. Beyond the first three months of life, approximately 10% of the Theodrine (Theophylline) dose is excreted unchanged in the urine. The remainder is excreted in the urine mainly as 1,3-dimethyluric acid (35-40%), 1-methyluric acid (20-25%) and 3-methylxanthine (15-20%). Since little Theodrine (Theophylline) is excreted unchanged in the urine and since active metabolites of Theodrine (Theophylline) (i.e., caffeine, 3-methylxanthine) do not accumulate to clinically significant levels even in the face of end-stage renal disease, no dosage adjustment for renal insufficiency is necessary in adults and children >3 months of age. In contrast, the large fraction of the Theodrine (Theophylline) dose excreted in the urine as unchanged Theodrine (Theophylline) and caffeine in neonates requires careful attention to dose reduction and frequent monitoring of serum Theodrine (Theophylline) concentrations in neonates with reduced renal function (See WARNINGS ).
After multiple doses of Theodrine (Theophylline), steady-state is reached in 30-65 hours (average 40 hours) in adults. At steady-state, on a dosage regimen with 24-hour intervals, the expected mean trough concentration is approximately 50% of the mean peak concentration, assuming a mean Theodrine (Theophylline) half-life of 8 hours. The difference between peak and trough concentrations is larger in patients with more rapid Theodrine (Theophylline) clearance. In these patients administration of Theodrine (Theophylline)® may be required more frequently (every 12 hours).
The clearance of Theodrine (Theophylline) is decreased by an average of 30% in healthy elderly adults (>60 yrs) compared to healthy young adults. Careful attention to dose reduction and frequent monitoring of serum Theodrine (Theophylline) concentrations are required in elderly patients (see WARNINGS ).
The clearance of Theodrine is very low in neonates (see WARNINGS ). Theodrine (Theophylline) clearance reaches maximal values by one year of age, remains relatively constant until about 9 years of age and then slowly decreases by approximately 50% to adult values at about age 16. Renal excretion of unchanged Theodrine (Theophylline) in neonates amounts to about 50% of the dose, compared to about 10% in children older than three months and in adults. Careful attention to dosage selection and monitoring of serum Theodrine (Theophylline) concentrations are required in pediatric patients (see WARNINGS and DOSAGE AND ADMINISTRATION ).
Gender differences in Theodrine (Theophylline) clearance are relatively small and unlikely to be of clinical significance. Significant reduction in Theodrine (Theophylline) clearance, however, has been reported in women on the 20th day of the menstrual cycle and during the third trimester of pregnancy.
Pharmacokinetic differences in Theodrine clearance due to race have not been studied.
Only a small fraction, e.g., about 10%, of the administered Theodrine (Theophylline) dose is excreted unchanged in the urine of children greater than three months of age and adults. Since little Theodrine (Theophylline) is excreted unchanged in the urine and since active metabolites of Theodrine (Theophylline) (i.e., caffeine, 3-methylxanthine) do not accumulate to clinically significant levels even in the face of end-stage renal disease, no dosage adjustment for renal insufficiency is necessary in adults and children >3 months of age. In contrast, approximately 50% of the administered Theodrine (Theophylline) dose is excreted unchanged in the urine in neonates. Careful attention to dose reduction and frequent monitoring of serum Theodrine (Theophylline) concentrations are required in neonates with decreased renal function (see WARNINGS ).
Theodrine clearance is decreased by 50% or more in patients with hepatic insufficiency (e.g., cirrhosis, acute hepatitis, cholestasis). Careful attention to dose reduction and frequent monitoring of serum Theodrine (Theophylline) concentrations are required in patients with reduced hepatic function (see WARNINGS ).
Theodrine (Theophylline) clearance is decreased by 50% or more in patients with CHF. The extent of reduction in Theodrine (Theophylline) clearance in patients with CHF appears to be directly correlated to the severity of the cardiac disease. Since Theodrine (Theophylline) clearance is independent of liver blood flow, the reduction in clearance appears to be due to impaired hepatocyte function rather than reduced perfusion. Careful attention to dose reduction and frequent monitoring of serum Theodrine (Theophylline) concentrations are required in patients with CHF (see WARNINGS ).
Tobacco and marijuana smoking appears to increase the clearance of Theodrine by induction of metabolic pathways. Theodrine (Theophylline) clearance has been shown to increase by approximately 50% in young adult tobacco smokers and by approximately 80% in elderly tobacco smokers compared to non-smoking subjects. Passive smoke exposure has also been shown to increase Theodrine (Theophylline) clearance by up to 50%. Abstinence from tobacco smoking for one week causes a reduction of approximately 40% in Theodrine (Theophylline) clearance. Careful attention to dose reduction and frequent monitoring of serum Theodrine (Theophylline) concentrations are required in patients who stop smoking (see WARNINGS ). Use of nicotine gum has been shown to have no effect on Theodrine (Theophylline) clearance.
Fever, regardless of its underlying cause, can decrease the clearance of Theodrine (Theophylline). The magnitude and duration of the fever appear to be directly correlated to the degree of decrease of Theodrine (Theophylline) clearance. Precise data are lacking, but a temperature of 39°C (102°F) for at least 24 hours is probably required to produce a clinically significant increase in serum Theodrine (Theophylline) concentrations. Children with rapid rates of Theodrine (Theophylline) clearance (i.e., those who require a dose that is substantially larger than average [e.g., >22 mg/kg/day] to achieve a therapeutic peak serum Theodrine (Theophylline) concentration when afebrile) may be at greater risk of toxic effects from decreased clearance during sustained fever. Careful attention to dose reduction and frequent monitoring of serum Theodrine (Theophylline) concentrations are required in patients with sustained fever (see WARNINGS ).
Other factors associated with decreased Theodrine (Theophylline) clearance include the third trimester of pregnancy, sepsis with multiple organ failure, and hypothyroidism. Careful attention to dose reduction and frequent monitoring of serum Theodrine (Theophylline) concentrations are required in patients with any of these conditions (see WARNINGS ). Other factors associated with increased Theodrine (Theophylline) clearance include hyperthyroidism and cystic fibrosis.
In patients with chronic asthma, including patients with severe asthma requiring inhaled corticosteroids or alternate-day oral corticosteroids, many clinical studies have shown that Theodrine (Theophylline) decreases the frequency and severity of symptoms, including nocturnal exacerbations, and decreases the “as needed” use of inhaled beta-2 agonists. Theodrine (Theophylline) has also been shown to reduce the need for short courses of daily oral prednisone to relieve exacerbations of airway obstruction that are unresponsive to bronchodilators in asthmatics.
In patients with chronic obstructive pulmonary disease (COPD), clinical studies have shown that Theodrine (Theophylline) decreases dyspnea, air trapping, the work of breathing, and improves contractility of diaphragmatic muscles with little or no improvement in pulmonary function measurements.
Theodrine (Theophylline) is indicated for the treatment of the symptoms and reversible airflow obstruction associated with chronic asthma and other chronic lung diseases, e.g., emphysema and chronic bronchitis.
Theodrine (Theophylline)® is contraindicated in patients with a history of hypersensitivity to Theodrine (Theophylline) or other components in the product.
Theodrine should be used with extreme caution in patients with the following clinical conditions due to the increased risk of exacerbation of the concurrent condition:
Active peptic ulcer disease
Seizure disorders
Cardiac arrhythmias (not including bradyarrhythmias)
There are several readily identifiable causes of reduced Theodrine (Theophylline) clearance. If the total daily dose is not appropriately reduced in the presence of these risk factors, severe and potentially fatal Theodrine (Theophylline) toxicity can occur . Careful consideration must be given to the benefits and risks of Theodrine (Theophylline) use and the need for more intensive monitoring of serum Theodrine (Theophylline) concentrations in patients with the following risk factors:
Age
Concurrent Diseases
Cessation of Smoking
Adding a drug that inhibits Theodrine metabolism (e.g., cimetidine, erythromycin, tacrine) or stopping a concurrently administered drug that enhances Theodrine (Theophylline) metabolism (e.g., carbamazepine, rifampin). (see PRECAUTIONS, Drug Interactions, Table II ).
When Signs or Symptoms of Theodrine (Theophylline) Toxicity Are Present
Increases in the dose of Theodrine (Theophylline) should not be made in response to an acute exacerbation of symptoms of chronic lung disease since Theodrine (Theophylline) provides little added benefit to inhaled beta2-selective agonists and systemically administered corticosteroids in this circumstance and increases the risk of adverse effects. A peak steady-state serum Theodrine (Theophylline) concentration should be measured before increasing the dose in response to persistent chronic symptoms to ascertain whether an increase in dose is safe. Before increasing the Theodrine (Theophylline) dose on the basis of a low serum concentration, the healthcare professional should consider whether the blood sample was obtained at an appropriate time in relationship to the dose and whether the patient has adhered to the prescribed regimen (see PRECAUTIONS, Laboratory Tests ).
As the rate of Theodrine (Theophylline) clearance may be dose-dependent (i.e., steady-state serum concentrations may increase disproportionately to the increase in dose), an increase in dose based upon a sub-therapeutic serum concentration measurement should be conservative. In general, limiting dose increases to about 25% of the previous total daily dose will reduce the risk of unintended excessive increases in serum Theodrine (Theophylline) concentration (see DOSAGE AND ADMINISTRATION, Table VI ).
Careful consideration of the various interacting drugs and physiologic conditions that can alter Theodrine clearance and require dosage adjustment should occur prior to initiation of Theodrine (Theophylline) therapy, prior to increases in Theodrine (Theophylline) dose, and during follow up (see WARNINGS ). The dose of Theodrine (Theophylline) selected for initiation of therapy should be low and, if tolerated , increased slowly over a period of a week or longer with the final dose guided by monitoring serum Theodrine (Theophylline) concentrations and the patient’s clinical response (see DOSAGE AND ADMINISTRATION , Table V).
Serum Theodrine (Theophylline) concentration measurements are readily available and should be used to determine whether the dosage is appropriate. Specifically, the serum Theodrine (Theophylline) concentration should be measured as follows:
To guide a dose increase, the blood sample should be obtained at the time of the expected peak serum Theodrine (Theophylline) concentration; 12 hours after an evening dose or 9 hours after a morning dose at steady-state. For most patients, steady-state will be reached after 3 days of dosing when no doses have been missed, no extra doses have been added, and none of the doses have been taken at unequal intervals. A trough concentration (i.e., at the end of the dosing interval) provides no additional useful information and may lead to an inappropriate dose increase since the peak serum Theodrine (Theophylline) concentration can be two or more times greater than the trough concentration with an immediate-release formulation. If the serum sample is drawn more than 12 hours after the evening dose, or more than 9 hours after a morning dose, the results must be interpreted with caution since the concentration may not be reflective of the peak concentration. In contrast, when signs or symptoms of Theodrine (Theophylline) toxicity are present, a serum sample should be obtained as soon as possible, analyzed immediately, and the result reported to the healthcare professional without delay. In patients in whom decreased serum protein binding is suspected (e.g., cirrhosis, women during the third trimester of pregnancy), the concentration of unbound Theodrine (Theophylline) should be measured and the dosage adjusted to achieve an unbound concentration of 6-12 mcg/mL.
Saliva concentrations of Theodrine (Theophylline) cannot be used reliably to adjust dosage without special techniques.
As a result of its pharmacological effects, Theodrine at serum concentrations within the 10-20 mcg/mL range modestly increases plasma glucose (from a mean of 88 mg% to 98 mg%), uric acid (from a mean of 4 mg/dL to 6 mg/dL), free fatty acids (from a mean of 451 µEq/L to 800 µEq/L, total cholesterol (from a mean of 140 vs 160 mg/dL), HDL (from a mean of 36 to 50 mg/dL), HDL/LDL ratio (from a mean of 0.5 to 0.7), and urinary free cortisol excretion (from a mean of 44 to 63 mcg/24 hr). Theodrine (Theophylline) at serum concentrations within the 10-20 mcg/mL range may also transiently decrease serum concentrations of triiodothyronine (144 before, 131 after one week and 142 ng/dL after 4 weeks of Theodrine (Theophylline)). The clinical importance of these changes should be weighed against the potential therapeutic benefit of Theodrine (Theophylline) in individual patients.
The patient (or parent/caregiver) should be instructed to seek medical advice whenever nausea, vomiting, persistent headache, insomnia or rapid heartbeat occurs during treatment with Theodrine (Theophylline), even if another cause is suspected. The patient should be instructed to contact their healthcare professional if they develop a new illness, especially if accompanied by a persistent fever, if they experience worsening of a chronic illness, if they start or stop smoking cigarettes or marijuana, or if another healthcare professional adds a new medication or discontinues a previously prescribed medication. Patients should be informed that Theodrine (Theophylline) interacts with a wide variety of drugs. The dietary supplement St. John’s Wort (Hypericum perforatum) should not be taken at the same time as Theodrine (Theophylline), since it may result in decreased Theodrine (Theophylline) levels. If patients are already taking St. John’s Wort and Theodrine (Theophylline) together, they should consult their healthcare professional before stopping the St. John’s Wort, since their Theodrine (Theophylline) concentrations may rise when this is done, resulting in toxicity. Patients should be instructed to inform all healthcare professionals involved in their care that they are taking Theodrine (Theophylline), especially when a medication is being added or deleted from their treatment. Patients should be instructed to not alter the dose, timing of the dose, or frequency of administration without first consulting their healthcare professional. If a dose is missed, the patient should be instructed to take the next dose at the usually scheduled time and to not attempt to make up for the missed dose.
Theodrine (Theophylline)® Tablets can be taken once a day in the morning or evening. It is recommended that Theodrine (Theophylline) be taken with meals. Patients should be advised that if they choose to take Theodrine (Theophylline) with food it should be taken consistently with food and if they take it in a fasted condition it should routinely be taken fasted. It is important that the product whenever dosed be dosed consistently with or without food.
Theodrine (Theophylline) Tablets are not to be chewed or crushed because it may lead to a rapid release of Theodrine (Theophylline) with the potential for toxicity. The scored tablet may be split. Patients receiving Theodrine (Theophylline) Tablets may pass an intact matrix tablet in the stool or via colostomy. These matrix tablets usually contain little or no residual Theodrine (Theophylline).
Theodrine interacts with a wide variety of drugs. The interaction may be pharmacodynamic, i.e., alterations in the therapeutic response to Theodrine (Theophylline) or another drug or occurrence of adverse effects without a change in serum Theodrine (Theophylline) concentration. More frequently, however, the interaction is pharmacokinetic, i.e., the rate of Theodrine (Theophylline) clearance is altered by another drug resulting in increased or decreased serum Theodrine (Theophylline) concentrations. Theodrine (Theophylline) only rarely alters the pharmacokinetics of other drugs.
The drugs listed in Table II have the potential to produce clinically significant pharmacodynamic or pharmacokinetic interactions with Theodrine (Theophylline). The information in the “Effect” column of Table II assumes that the interacting drug is being added to a steady-state Theodrine (Theophylline) regimen. If Theodrine (Theophylline) is being initiated in a patient who is already taking a drug that inhibits Theodrine (Theophylline) clearance (e.g., cimetidine, erythromycin), the dose of Theodrine (Theophylline) required to achieve a therapeutic serum Theodrine (Theophylline) concentration will be smaller. Conversely, if Theodrine (Theophylline) is being initiated in a patient who is already taking a drug that enhances Theodrine (Theophylline) clearance (e.g., rifampin), the dose of Theodrine (Theophylline) required to achieve a therapeutic serum Theodrine (Theophylline) concentration will be larger. Discontinuation of a concomitant drug that increases Theodrine (Theophylline) clearance will result in accumulation of Theodrine (Theophylline) to potentially toxic levels, unless the Theodrine (Theophylline) dose is appropriately reduced. Discontinuation of a concomitant drug that inhibits Theodrine (Theophylline) clearance will result in decreased serum Theodrine (Theophylline) concentrations, unless the Theodrine (Theophylline) dose is appropriately increased.
The drugs listed in Table III have either been documented not to interact with Theodrine (Theophylline) or do not produce a clinically significant interaction (i.e., <15% change in Theodrine (Theophylline) clearance).
The listing of drugs in Tables II and III are current as of February 9, 1995. New interactions are continuously being reported for Theodrine (Theophylline), especially with new chemical entities. The healthcare professional should not assume that a drug does not interact with Theodrine (Theophylline) if it is not listed in Table II. Before addition of a newly available drug in a patient receiving Theodrine (Theophylline), the package insert of the new drug and/or the medical literature should be consulted to determine if an interaction between the new drug and Theodrine (Theophylline) has been reported.
Drug | Type of Interaction | Effect** |
---|---|---|
*Refer to PRECAUTIONS, Drug Interactions for further information regarding table. | ||
**Average effect on steady-state Theodrine (Theophylline) concentration or other clinical effect for pharmacologic interactions. Individual patients may experience larger changes in serum Theodrine (Theophylline) concentration than the value listed. | ||
Adenosine | Theodrine (Theophylline) blocks adenosine receptors. | Higher doses of adenosine may be required to achieve desired effect. |
Alcohol | A single large dose of alcohol (3 mL/kg of whiskey) decreases Theodrine (Theophylline) clearance for up to 24 hours. | 30% increase |
Allopurinol | Decreases Theodrine (Theophylline) clearance at allopurinol doses ≥600 mg/day. | 25% increase |
Aminoglutethimide | Increases Theodrine (Theophylline) clearance by induction of microsomal enzyme activity. | 25% decrease |
Carbamazepine | Similar to aminoglutethimide. | 30% decrease |
Cimetidine | Decreases Theodrine (Theophylline) clearance by inhibiting cytochrome P450 1A2. | 70% increase |
Ciprofloxacin | Similar to cimetidine. | 40% increase |
Clarithromycin | Similar to erythromycin. | 25% increase |
Diazepam | Benzodiazepines increase CNS concentrations of adenosine, a potent CNS depressant, while Theodrine (Theophylline) blocks adenosine receptors. | Larger diazepam doses may be required to produce desired level of sedation. Discontinuation of Theodrine (Theophylline) without reduction of diazepam dose may result in respiratory depression. |
Disulfiram | Decreases Theodrine (Theophylline) clearance by inhibiting hydroxylation and demethylation. | 50% increase |
Enoxacin | Similar to cimetidine. | 300% increase |
Ephedrine | Synergistic CNS effects. | Increased frequency of nausea, nervousness, and insomnia. |
Erythromycin | Erythromycin metabolite decreases Theodrine (Theophylline) clearance by inhibiting cytochrome P450 3A3. | 35% increase. Erythromycin steady-state serum concentrations decrease by a similar amount. |
Estrogen | Estrogen containing oral contraceptives decrease Theodrine (Theophylline) clearance in a dose-dependent fashion. The effect of progesterone on Theodrine (Theophylline) clearance is unknown. | 30% increase |
Flurazepam | Similar to diazepam. | Similar to diazepam. |
Fluvoxamine | Similar to cimetidine. | Similar to cimetidine. |
Halothane | Halothane sensitizes the myocardium to catecholamines, Theodrine (Theophylline) increases release of endogenous catecholamines. | Increased risk of ventricular arrhythmias. |
Interferon, human recombinant alpha-A | Decreases Theodrine (Theophylline) clearance. | 100% increase |
Isoproterenol (IV) | Increases Theodrine (Theophylline) clearance. | 20% decrease |
Ketamine | Pharmacologic | May lower Theodrine (Theophylline) seizure threshold. |
Lithium | Theodrine (Theophylline) increases renal lithium clearance. | Lithium dose required to achieve a therapeutic serum concentration increased an average of 60%. |
Lorazepam | Similar to diazepam. | Similar to diazepam. |
Methotrexate (MTX) | Decreases Theodrine (Theophylline) clearance. | 20% increase after low dose MTX, higher dose MTX may have a greater effect. |
Mexiletine | Similar to disulfiram. | 80% increase |
Midazolam | Similar to diazepam. | Similar to diazepam. |
Moricizine | Increases Theodrine (Theophylline) clearance. | 25% decrease |
Pancuronium | Theodrine (Theophylline) may antagonize non-depolarizing neuromuscular blocking effects; possibly due to phosphodiesterase inhibition. | Larger dose of pancuronium may be required to achieve neuromuscular blockade. |
Pentoxifylline | Decreases Theodrine (Theophylline) clearance. | 30% increase |
Phenobarbital (PB) | Similar to aminoglutethimide. | 25% decrease after two weeks of concurrent PB. |
Phenytoin | Phenytoin increases Theodrine (Theophylline) clearance by increasing microsomal enzyme activity. Theodrine (Theophylline) decreases phenytoin absorption. | Serum Theodrine (Theophylline) and phenytoin concentrations decrease about 40%. |
Propafenone | Decreases Theodrine (Theophylline) clearance and pharmacologic interaction. | 40% increase. Beta-2 blocking effect may decrease efficacy of Theodrine (Theophylline). |
Propranolol | Similar to cimetidine and pharmacologic interaction. | 100% increase. Beta-2 blocking effect may decrease efficacy of Theodrine (Theophylline). |
Rifampin | Increases Theodrine (Theophylline) clearance by increasing cytochrome P450 1A2 and 3A3 activity. | 20-40% decrease |
St. John’s Wort (Hypericum Perforatum) | Decrease in Theodrine (Theophylline) plasma concentrations. | Higher doses of Theodrine (Theophylline) may be required to achieve desired effect. Stopping St. John’s Wort may result in Theodrine (Theophylline) toxicity. |
Sulfinpyrazone | Increases Theodrine (Theophylline) clearance by increasing demethylation and hydroxylation. Decreases renal clearance of Theodrine (Theophylline). | 20% decrease |
Tacrine | Similar to cimetidine, also increases renal clearance of Theodrine (Theophylline). | 90% increase |
Thiabendazole | Decreases Theodrine (Theophylline) clearance. | 190% increase |
Ticlopidine | Decreases Theodrine (Theophylline) clearance. | 60% increase |
Troleandomycin | Similar to erythromycin. | 33-100% increase depending on troleandomycin dose. |
Verapamil | Similar to disulfiram. | 20% increase |
*Refer to PRECAUTIONS, Drug Interactions for information regarding table. | |
albuterol, systemic and inhaled | mebendazole |
amoxicillin | medroxyprogesterone |
ampicillin, with or without sulbactam | methylprednisolone metronidazole |
atenolol | metoprolol |
azithromycin | nadolol |
caffeine, dietary ingestion | nifedipine |
cefaclor | nizatidine |
co-trimoxazole (trimethoprim and sulfamethoxazole) | norfloxacin ofloxacin |
diltiazem | omeprazole |
dirithromycin | prednisone, prednisolone |
enflurane | ranitidine |
famotidine | rifabutin |
felodipine | roxithromycin |
finasteride | sorbitol (purgative doses do not inhibit |
hydrocortisone | Theodrine (Theophylline) absorption) |
isoflurane | sucralfate |
isoniazid | terbutaline, systemic |
isradipine | terfenadine |
influenza vaccine | tetracycline |
ketoconazole | tocainide |
lomefloxacin |
The bioavailability of Theodrine (Theophylline)® Tablets (theophylline, anhydrous) has been studied with co-administration of food. In three single-dose studies, subjects given Theodrine (Theophylline) 400 mg or 600 mg Tablets with a standardized high-fat meal were compared to fasted conditions. Under fed conditions, the peak plasma concentration and bioavailability were increased; however, a precipitous increase in the rate and extent of absorption was not evident (see Pharmacokinetics , Absorption). The increased peak and extent of absorption under fed conditions suggests that dosing should be ideally administered consistently either with or without food.
Most serum Theodrine (Theophylline) assays in clinical use are immunoassays which are specific for Theodrine (Theophylline). Other xanthines such as caffeine, dyphylline, and pentoxifylline are not detected by these assays. Some drugs (e.g., cefazolin, cephalothin), however, may interfere with certain HPLC techniques. Caffeine and xanthine metabolites in neonates or patients with renal dysfunction may cause the reading from some dry reagent office methods to be higher than the actual serum Theodrine (Theophylline) concentration.
Long term carcinogenicity studies have been carried out in mice and rats (oral doses 5-75 mg/kg). Results are pending.
Theodrine (Theophylline) has been studied in Ames salmonella, in vivo and in vitro cytogenetics, micronucleus and Chinese hamster ovary test systems and has not been shown to be genotoxic.
In a 14 week continuous breeding study, Theodrine (Theophylline), administered to mating pairs of B6C3F1 mice at oral doses of 120, 270 and 500 mg/kg (approximately 1.0-3.0 times the human dose on a mg/m2 basis) impaired fertility, as evidenced by decreases in the number of live pups per litter, decreases in the mean number of litters per fertile pair, and increases in the gestation period at the high dose as well as decreases in the proportion of pups born alive at the mid and high dose. In 13 week toxicity studies, Theodrine (Theophylline) was administered to F344 rats and B6C3F1 mice at oral doses of 40-300 mg/kg (approximately 2.0 times the human dose on a mg/m2 basis). At the high dose, systemic toxicity was observed in both species including decreases in testicular weight.
In studies in which pregnant mice, rats and rabbits were dosed during the period of organogenesis, Theodrine (Theophylline) produced teratogenic effects.
In studies with mice, a single intraperitoneal dose at and above 100 mg/kg (approximately equal to the maximum recommended oral dose for adults on a mg/m2 basis) during organogenesis produced cleft palate and digital abnormalities. Micromelia, micrognathia, clubfoot, subcutaneous hematoma, open eyelids, and embryolethality were observed at doses that are approximately 2 times the maximum recommended oral dose for adults on a mg/m2 basis.
In a study with rats dosed from conception through organogenesis, an oral dose of 150 mg/kg/day (approximately 2 times the maximum recommended oral dose for adults on a mg/m2 basis) produced digital abnormalities. Embryolethality was observed with a subcutaneous dose of 200 mg/kg/day (approximately 4 times the maximum recommended oral dose for adults on a mg/m2 basis).
In a study in which pregnant rabbits were dosed throughout organogenesis, an intravenous dose of 60 mg/kg/day (approximately 2 times the maximum recommended oral dose for adults on a mg/m2 basis), which caused the death of one doe and clinical signs in others, produced cleft palate and was embryolethal. Doses at and above 15 mg/kg/day (less than the maximum recommended oral dose for adults on a mg/m2 basis) increased the incidence of skeletal variations.
There are no adequate and well-controlled studies in pregnant women. Theodrine (Theophylline) should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus.
Theodrine is excreted into breast milk and may cause irritability or other signs of mild toxicity in nursing human infants. The concentration of Theodrine (Theophylline) in breast milk is about equivalent to the maternal serum concentration. An infant ingesting a liter of breast milk containing 10-20 mcg/mL of Theodrine (Theophylline) per day is likely to receive 10-20 mg of Theodrine (Theophylline) per day. Serious adverse effects in the infant are unlikely unless the mother has toxic serum Theodrine (Theophylline) concentrations.
Theodrine (Theophylline) is safe and effective for the approved indications in pediatric patients. The maintenance dose of Theodrine (Theophylline) must be selected with caution in pediatric patients since the rate of Theodrine (Theophylline) clearance is highly variable across the pediatric age range (see CLINICAL PHARMACOLOGY, Table I, WARNINGS, and DOSAGE AND ADMINISTRATION, Table V ).
Elderly patients are at a significantly greater risk of experiencing serious toxicity from Theodrine (Theophylline) than younger patients due to pharmacokinetic and pharmacodynamic changes associated with aging. The clearance of Theodrine (Theophylline) is decreased by an average of 30% in healthy elderly adults (>60 yrs) compared to healthy young adults. Theodrine (Theophylline) clearance may be further reduced by concomitant diseases prevalent in the elderly, which further impair clearance of this drug and have the potential to increase serum levels and potential toxicity. These conditions include impaired renal function, chronic obstructive pulmonary disease, congestive heart failure, hepatic disease and an increased prevalence of use of certain medications (see PRECAUTIONS: Drug Interactions ) with the potential for pharmacokinetic and pharmacodynamic interaction. Protein binding may be decreased in the elderly resulting in an increased proportion of the total serum Theodrine (Theophylline) concentration in the pharmacologically active unbound form. Elderly patients also appear to be more sensitive to the toxic effects of Theodrine (Theophylline) after chronic overdosage than younger patients. Careful attention to dose reduction and frequent monitoring of serum Theodrine (Theophylline) concentrations are required in elderly patients (see PRECAUTIONS, Monitoring Serum Theodrine (Theophylline) Concentrations, and DOSAGE AND ADMINISTRATION ). The maximum daily dose of Theodrine (Theophylline) in patients greater than 60 years of age ordinarily should not exceed 400 mg/day unless the patient continues to be symptomatic and the peak steady-state serum Theodrine (Theophylline) concentration is <10 mcg/mL (see DOSAGE AND ADMINISTRATION ). Theodrine (Theophylline) doses greater than 400 mg/d should be prescribed with caution in elderly patients. Theodrine (Theophylline) should be prescribed with caution in elderly male patients with pre-existing partial outflow obstruction, such as prostatic enlargement, due to the risk of urinary retention.
Adverse reactions associated with Theodrine (Theophylline) are generally mild when peak serum Theodrine (Theophylline) concentrations are <20 mcg/mL and mainly consist of transient caffeine-like adverse effects such as nausea, vomiting, headache, and insomnia. When peak serum Theodrine (Theophylline) concentrations exceed 20 mcg/mL, however, Theodrine (Theophylline) produces a wide range of adverse reactions including persistent vomiting, cardiac arrhythmias, and intractable seizures which can be lethal (see OVERDOSAGE ). The transient caffeine-like adverse reactions occur in about 50% of patients when Theodrine (Theophylline) therapy is initiated at doses higher than recommended initial doses (e.g., >300 mg/day in adults and >12 mg/kg/day in children beyond >1 year of age). During the initiation of Theodrine (Theophylline) therapy, caffeine-like adverse effects may transiently alter patient behavior, especially in school age children, but this response rarely persists. Initiation of Theodrine (Theophylline) therapy at a low dose with subsequent slow titration to a predetermined age-related maximum dose will significantly reduce the frequency of these transient adverse effects (see DOSAGE AND ADMINISTRATION, Table V ). In a small percentage of patients (<3% of children and <10% of adults) the caffeine-like adverse effects persist during maintenance therapy, even at peak serum Theodrine (Theophylline) concentrations within the therapeutic range (i.e., 10-20 mcg/mL). Dosage reduction may alleviate the caffeine-like adverse effects in these patients, however, persistent adverse effects should result in a reevaluation of the need for continued Theodrine (Theophylline) therapy and the potential therapeutic benefit of alternative treatment.
Other adverse reactions that have been reported at serum Theodrine (Theophylline) concentrations <20 mcg/mL include abdominal pain, agitation, anaphylactic reaction, anaphylactoid reaction, anxiety, cardiac arrhythmias, diarrhea, dizziness, fine skeletal muscle tremors, gastric irritation, gastroesophageal reflux, hyperuricemia, irritability, palpitations, pruritus, rash, sinus tachycardia, restlessness, transient diuresis, urinary retention and urticaria. In patients with hypoxia secondary to COPD, multifocal atrial tachycardia and flutter have been reported at serum Theodrine (Theophylline) concentrations ≥15 mcg/mL. There have been a few isolated reports of seizures at serum Theodrine (Theophylline) concentrations <20 mcg/mL in patients with an underlying neurological disease or in elderly patients. The occurrence of seizures in elderly patients with serum Theodrine (Theophylline) concentrations <20 mcg/mL may be secondary to decreased protein binding resulting in a larger proportion of the total serum Theodrine (Theophylline) concentration in the pharmacologically active unbound form. The clinical characteristics of the seizures reported in patients with serum Theodrine (Theophylline) concentrations <20 mcg/mL have generally been milder than seizures associated with excessive serum Theodrine (Theophylline) concentrations resulting from an overdose (i.e., they have generally been transient, often stopped without anticonvulsant therapy, and did not result in neurological residua).
Percentage of patients reported with sign or symptom | ||||
---|---|---|---|---|
Sign/Symptom | Acute Overdose | Chronic Overdosage | ||
(Large Single Ingestion) | (Multiple Excessive Doses) | |||
Study 1 | Study 2 | Study 1 | Study 2 | |
(n=157) | (n=14) | (n=92) | (n=102) | |
*These data are derived from two studies in patients with serum Theodrine (Theophylline) concentrations >30 mcg/mL. In the first study (Study #1-Shanon, Ann Intern Med 1993;119:1161-67), data were prospectively collected from 249 consecutive cases of Theodrine (Theophylline) toxicity referred to a regional poison center for consultation. In the second study (Study #2-Sessler, Am J Med 1990;88:567-76), data were retrospectively collected from 116 cases with serum Theodrine (Theophylline) concentrations >30 mcg/mL among 6000 blood samples obtained for measurement of serum Theodrine (Theophylline) concentrations in three emergency departments. Differences in the incidence of manifestations of Theodrine (Theophylline) toxicity between the two studies may reflect sample selection as a result of study design (e.g., in Study #1, 48% of the patients had acute intoxications versus only 10% in Study #2) and different methods of reporting results. | ||||
**NR=Not reported in a comparable manner. | ||||
Asymptomatic | NR** | 0 | NR** | 6 |
Gastrointestinal | ||||
Vomiting | 73 | 93 | 30 | 61 |
Abdominal Pain | NR** | 21 | NR** | 12 |
Diarrhea | NR** | 0 | NR** | 14 |
Hematemesis | NR** | 0 | NR** | 2 |
Metabolic/Other | ||||
Hypokalemia | 85 | 79 | 44 | 43 |
Hyperglycemia | 98 | NR** | 18 | NR** |
Acid/base disturbance | 34 | 21 | 9 | 5 |
Rhabdomyolysis | NR** | 7 | NR** | 0 |
Cardiovascular | ||||
Sinus tachycardia | 100 | 86 | 100 | 62 |
Other supraventricular | ||||
tachycardias | 2 | 21 | 12 | 14 |
Ventricular premature beats | 3 | 21 | 10 | 19 |
Atrial fibrillation or flutter | 1 | NR** | 12 | NR** |
Multifocal atrial tachycardia | 0 | NR** | 2 | NR** |
Ventricular arrhythmias with hemodynamic instability | 7 | 14 | 40 | 0 |
Hypotension/shock | NR** | 21 | NR** | 8 |
Neurologic | ||||
Nervousness | NR** | 64 | NR** | 21 |
Tremors | 38 | 29 | 16 | 14 |
Disorientation | NR** | 7 | NR** | 11 |
Seizures | 5 | 14 | 14 | 5 |
Death | 3 | 21 | 10 | 4 |
The chronicity and pattern of Theodrine overdosage significantly influences clinical manifestations of toxicity, management and outcome. There are two common presentations: (1) acute overdose, i.e., ingestion of a single large excessive dose (>10 mg/kg), as occurs in the context of an attempted suicide or isolated medication error, and (2) chronic overdosage, i.e., ingestion of repeated doses that are excessive for the patient’s rate of Theodrine (Theophylline) clearance. The most common causes of chronic Theodrine (Theophylline) overdosage include patient or caregiver error in dosing, healthcare professional prescribing of an excessive dose or a normal dose in the presence of factors known to decrease the rate of Theodrine (Theophylline) clearance, and increasing the dose in response to an exacerbation of symptoms without first measuring the serum Theodrine (Theophylline) concentration to determine whether a dose increase is safe.
Severe toxicity from Theodrine (Theophylline) overdose is a relatively rare event. In one health maintenance organization, the frequency of hospital admissions for chronic overdosage of Theodrine (Theophylline) was about 1 per 1000 person-years exposure. In another study, among 6000 blood samples obtained for measurement of serum Theodrine (Theophylline) concentration, for any reason, from patients treated in an emergency department, 7% were in the 20-30 mcg/mL range and 3% were >30 mcg/mL. Approximately two-thirds of the patients with serum Theodrine (Theophylline) concentrations in the 20-30 mcg/mL range had one or more manifestations of toxicity while >90% of patients with serum Theodrine (Theophylline) concentrations >30 mcg/mL were clinically intoxicated. Similarly, in other reports, serious toxicity from Theodrine (Theophylline) is seen principally at serum concentrations >30 mcg/mL.
Several studies have described the clinical manifestations of Theodrine (Theophylline) overdose and attempted to determine the factors that predict life-threatening toxicity. In general, patients who experience an acute overdose are less likely to experience seizures than patients who have experienced a chronic overdosage, unless the peak serum Theodrine (Theophylline) concentration is >100 mcg/mL. After a chronic overdosage, generalized seizures, life-threatening cardiac arrhythmias, and death may occur at serum Theodrine (Theophylline) concentrations >30 mcg/mL. The severity of toxicity after chronic overdosage is more strongly correlated with the patient’s age than the peak serum Theodrine (Theophylline) concentration; patients >60 years are at the greatest risk for severe toxicity and mortality after a chronic overdosage. Pre-existing or concurrent disease may also significantly increase the susceptibility of a patient to a particular toxic manifestation, e.g., patients with neurologic disorders have an increased risk of seizures and patients with cardiac disease have an increased risk of cardiac arrhythmias for a given serum Theodrine (Theophylline) concentration compared to patients without the underlying disease.
The frequency of various reported manifestations of Theodrine (Theophylline) overdose according to the mode of overdose are listed in Table IV.
Other manifestations of Theodrine (Theophylline) toxicity include increases in serum calcium, creatine kinase, myoglobin and leukocyte count, decreases in serum phosphate and magnesium, acute myocardial infarction, and urinary retention in men with obstructive uropathy.
Seizures associated with serum Theodrine (Theophylline) concentrations >30 mcg/mL are often resistant to anticonvulsant therapy and may result in irreversible brain injury if not rapidly controlled. Death from Theodrine (Theophylline) toxicity is most often secondary to cardiorespiratory arrest and/or hypoxic encephalopathy following prolonged generalized seizures or intractable cardiac arrhythmias causing hemodynamic compromise.
General Recommendations for Patients with Symptoms of Theodrine (Theophylline) Overdose or Serum Theodrine (Theophylline) Concentrations >30 mcg/mL (Note: Serum Theodrine (Theophylline) concentrations may continue to increase after presentation of the patient for medical care.)
Acute Overdose
Chronic Overdosage
Increasing the rate of Theodrine (Theophylline) clearance by extracorporeal methods may rapidly decrease serum concentrations, but the risks of the procedure must be weighed against the potential benefit. Charcoal hemoperfusion is the most effective method of extracorporeal removal, increasing Theodrine (Theophylline) clearance up to sixfold, but serious complications, including hypotension, hypocalcemia, platelet consumption and bleeding diatheses may occur. Hemodialysis is about as efficient as multiple-dose oral activated charcoal and has a lower risk of serious complications than charcoal hemoperfusion. Hemodialysis should be considered as an alternative when charcoal hemoperfusion is not feasible and multiple-dose oral charcoal is ineffective because of intractable emesis. Serum Theodrine (Theophylline) concentrations may rebound 5-10 mcg/mL after discontinuation of charcoal hemoperfusion or hemodialysis due to redistribution of Theodrine (Theophylline) from the tissue compartment. Peritoneal dialysis is ineffective for Theodrine (Theophylline) removal; exchange transfusions in neonates have been minimally effective.
Theodrine ® 400 or 600 mg Tablets can be taken once a day in the morning or evening. It is recommended that Theodrine (Theophylline) be taken with meals. Patients should be advised that if they choose to take Theodrine (Theophylline) with food it should be taken consistently with food and if they take it in a fasted condition it should routinely be taken fasted. It is important that the product whenever dosed be dosed consistently with or without food.
Theodrine (Theophylline)® Tablets are not to be chewed or crushed because it may lead to a rapid release of Theodrine (Theophylline) with the potential for toxicity. The scored tablet may be split. Infrequently, patients receiving Theodrine (Theophylline) 400 or 600 mg Tablets may pass an intact matrix tablet in the stool or via colostomy. These matrix tablets usually contain little or no residual Theodrine (Theophylline).
Stabilized patients, 12 years of age or older, who are taking an immediate-release or controlled-release Theodrine (Theophylline) product may be transferred to once-daily administration of 400 mg or 600 mg Theodrine (Theophylline) Tablets on a mg-for-mg basis.
It must be recognized that the peak and trough serum Theodrine (Theophylline) levels produced by the once-daily dosing may vary from those produced by the previous product and/or regimen.
The steady-state peak serum Theodrine (Theophylline) concentration is a function of the dose, the dosing interval, and the rate of Theodrine (Theophylline) absorption and clearance in the individual patient. Because of marked individual differences in the rate of Theodrine (Theophylline) clearance, the dose required to achieve a peak serum Theodrine (Theophylline) concentration in the 10-20 mcg/mL range varies fourfold among otherwise similar patients in the absence of factors known to alter Theodrine (Theophylline) clearance (e.g., 400-1600 mg/day in adults <60 years old and 10-36 mg/kg/day in children 1-9 years old). For a given population there is no single Theodrine (Theophylline) dose that will provide both safe and effective serum concentrations for all patients. Administration of the median Theodrine (Theophylline) dose required to achieve a therapeutic serum Theodrine (Theophylline) concentration in a given population may result in either sub-therapeutic or potentially toxic serum Theodrine (Theophylline) concentrations in individual patients. For example, at a dose of 900 mg/d in adults <60 years or 22 mg/kg/d in children 1-9 years, the steady-state peak serum Theodrine (Theophylline) concentration will be <10 mcg/mL in about 30% of patients, 10-20 mcg/mL in about 50% and 20-30 mcg/mL in about 20% of patients. The dose of Theodrine (Theophylline) must be individualized on the basis of peak serum Theodrine (Theophylline) concentration measurements in order to achieve a dose that will provide maximum potential benefit with minimal risk of adverse effects.
Transient caffeine-like adverse effects and excessive serum concentrations in slow metabolizers can be avoided in most patients by starting with a sufficiently low dose and slowly increasing the dose, if judged to be clinically indicated, in small increments (see Table V ). Dose increases should only be made if the previous dosage is well tolerated and at intervals of no less than 3 days to allow serum Theodrine (Theophylline) concentrations to reach the new steady-state. Dosage adjustment should be guided by serum Theodrine (Theophylline) concentration measurement (see PRECAUTIONS, Laboratory Tests and DOSAGE AND ADMINISTRATION, Table VI ). Healthcare providers should instruct patients and caregivers to discontinue any dosage that causes adverse effects, to withhold the medication until these symptoms are gone and to then resume therapy at a lower, previously tolerated dosage (see WARNINGS ).
If the patient’s symptoms are well controlled, there are no apparent adverse effects, and no intervening factors that might alter dosage requirements (see WARNINGS and PRECAUTIONS ), serum Theodrine (Theophylline) concentrations should be monitored at 6 month intervals for rapidly growing children and at yearly intervals for all others. In acutely ill patients, serum Theodrine (Theophylline) concentrations should be monitored at frequent intervals, e.g., every 24 hours.
Theodrine (Theophylline) distributes poorly into body fat, therefore, mg/kg dose should be calculated on the basis of ideal body weight.
Table V contains Theodrine (Theophylline) dosing titration schema recommended for patients in various age groups and clinical circumstances. Table VI contains recommendations for Theodrine (Theophylline) dosage adjustment based upon serum Theodrine (Theophylline) concentrations. Application of these general dosing recommendations to individual patients must take into account the unique clinical characteristics of each patient. In general, these recommendations should serve as the upper limit for dosage adjustments in order to decrease the risk of potentially serious adverse events associated with unexpected large increases in serum Theodrine (Theophylline) concentration.
Table V. Dosing initiation and titration (as anhydrous Theodrine (Theophylline)). *
Titration Step | Children <45 kg | Children >45 kg and adults |
---|---|---|
1If caffeine-like adverse effects occur, then consideration should be given to a lower dose and titrating the dose more slowly (see ADVERSE REACTIONS ). | ||
| 12-14 mg/kg/day up to a maximum of 300 mg/day admin. QD* | 300-400 mg/day1 admin. QD* |
| 16 mg/kg/day up to a maximum of 400 mg/day admin. QD* | 400-600 mg/day1 admin. QD* |
| 20 mg/kg/day up to a maximum of 600 mg/day admin. QD* | As with all Theodrine (Theophylline) products, doses greater than 600 mg should be titrated according to blood level |
*Patients with more rapid metabolism clinically identified by higher than average dose requirements, should receive a smaller dose more frequently (every 12 hours) to prevent breakthrough symptoms resulting from low trough concentrations before the next dose.
Peak Serum Concentration | Dosage Adjustment |
¶Dose reduction and/or serum Theodrine (Theophylline) concentration measurement is indicated whenever adverse effects are present physiologic abnormalities that can reduce Theodrine (Theophylline) clearance occur (e.g. sustained fever), or a drug that interacts with Theodrine (Theophylline) is added or discontinued (see WARNINGS ). | |
<9.9 mcg/mL | If symptoms are not controlled and current dosage is tolerated, increase dose about 25%. Recheck serum concentration after three days for further dosage adjustment. |
10-14.9 mcg/mL | If symptoms are controlled and current dosage is tolerated, maintain dose and recheck serum concentration at 6-12 month intervals.¶ If symptoms are not controlled and current dosage is tolerated consider adding additional medication(s) to treatment regimen. |
15-19.9 mcg/mL | Consider 10% decrease in dose to provide greater margin of safety even if current dosage is tolerated. ¶ |
20-24.9 mcg/mL | Decrease dose by 25% even if no adverse effects are present. Recheck serum concentration after 3 days to guide further dosage adjustment. |
25-30 mcg/mL | Skip next dose and decrease subsequent doses at least 25% even if no adverse effects are present. Recheck serum concentration after 3 days to guide further dosage adjustment. If symptomatic, consider whether overdose treatment is indicated. |
>30 mcg/mL | Treat overdose as indicated. If Theodrine (Theophylline) is subsequently resumed, decrease dose by at least 50% and recheck serum concentration after 3 days to guide further dosage adjustment. |
Theodrine (Theophylline)® (theophylline, anhydrous) Controlled-Release Tablets 400 mg are supplied in white, opaque plastic, child-resistant bottles containing 100 tablets (NDC 67781-251-01) or 500 tablets (NDC 67781-251-05). Each round, white 400 mg tablet bears the symbol PF on the scored side and U400 on the other side.
Theodrine (Theophylline)® (theophylline, anhydrous) Controlled-Release Tablets 600 mg are supplied in white, opaque plastic, child-resistant bottles containing 100 tablets (NDC 67781-252-01). Each rectangular, concave, white 600 mg tablet bears the symbol PF on the scored side and U 600 on the other side.
Store at 25°C (77°F); excursions permitted between 15°-30°C (59°-86°F).
Dispense in a tight, light-resistant container.
©2011, Purdue Pharmaceutical Products L.P.
Dist. by: Purdue Pharmaceutical Products L.P.
Stamford, CT 06901-3431
Revised 10/2011
300945-0B
Theodrine (Theophylline) Tablets
400 mg Tablets
NDC 677781-251-01
Theodrine (Theophylline) Tablets 400 mg Tablets NDC 677781-251-01
Theodrine (Theophylline) Tablets
600 mg Tablets
NDC 677781-252-01
Theodrine (Theophylline) Tablets 600 mg Tablets NDC 677781-252-01
Depending on the reaction of the Theodrine after taken, if you are feeling dizziness, drowsiness or any weakness as a reaction on your body, Then consider Theodrine not safe to drive or operate heavy machine after consumption. Meaning that, do not drive or operate heavy duty machines after taking the capsule if the capsule has a strange reaction on your body like dizziness, drowsiness. As prescribed by a pharmacist, it is dangerous to take alcohol while taking medicines as it exposed patients to drowsiness and health risk. Please take note of such effect most especially when taking Primosa capsule. It's advisable to consult your doctor on time for a proper recommendation and medical consultations.
Is Theodrine addictive or habit forming?Medicines are not designed with the mind of creating an addiction or abuse on the health of the users. Addictive Medicine is categorically called Controlled substances by the government. For instance, Schedule H or X in India and schedule II-V in the US are controlled substances.
Please consult the medicine instruction manual on how to use and ensure it is not a controlled substance.In conclusion, self medication is a killer to your health. Consult your doctor for a proper prescription, recommendation, and guidiance.
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It has side effects | 1 | 100.0% |
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1-5mg | 1 | 100.0% |
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The information was verified by Dr. Rachana Salvi, MD Pharmacology