Rifacom EZ Kit

How is the drug helping you?
advertisement

Rifacom EZ Kit uses

Rifacom EZ Kit consists of Ethambutol, Isoniazid, Pyrazinamide, Rifampin.

Ethambutol:


DESCRIPTION

Rifacom EZ Kit (Ethambutol) Rifacom EZ Kit (Ethambutol) hydrochloride is an oral chemotherapeutic agent which is specifically effective against actively growing microorganisms of the genus Mycobacterium, including M. tuberculosis. The structural formula is:

Rifacom EZ Kit (Ethambutol) 100 and 400 mg tablets contain the following inactive ingredients: Gelatin, Hydroxypropyl Methylcellulose, Magnesium Stearate, Sodium Lauryl Sulfate, Sorbitol, Stearic Acid, Sucrose, Titanium Dioxide and other ingredients.

Structural Formula

CLINICAL PHARMACOLOGY

Rifacom EZ Kit (Ethambutol), following a single oral dose of 25 mg/kg of body weight, attains a peak of 2 to 5 mg/mL in serum 2 to 4 hours after administration. When the drug is administered daily for longer periods of time at this dose, serum levels are similar. The serum level of Rifacom EZ Kit (Ethambutol) falls to undetectable levels by 24 hours after the last dose except in some patients with abnormal renal function. The intracellular concentrations of erythrocytes reach peak values approximately twice those of plasma and maintain this ratio throughout the 24 hours.

During the 24-hour period following oral administration of Rifacom EZ Kit (Ethambutol) approximately 50 percent of the initial dose is excreted unchanged in the urine, while an additional 8 to 15 percent appears in the form of metabolites. The main path of metabolism appears to be an initial oxidation of the alcohol to an aldehydic intermediate, followed by conversion to a dicarboxylic acid. From 20 to 22 percent of the initial dose is excreted in the feces as unchanged drug. No drug accumulation has been observed with consecutive single daily doses of 25 mg/kg in patients with normal kidney function, although marked accumulation has been demonstrated in patients with renal insufficiency.

Rifacom EZ Kit (Ethambutol) diffuses into actively growing mycobacterium cells such as tubercle bacilli. Rifacom EZ Kit (Ethambutol) appears to inhibit the synthesis of one or more metabolites, thus causing impairment of cell metabolism, arrest of multiplication, and cell death. No cross resistance with other available antimycobacterial agents has been demonstrated.

Rifacom EZ Kit (Ethambutol) has been shown to be effective against strains of Mycobacterium tuberculosis but does not seem to be active against fungi, viruses, or other bacteria. Mycobacterium tuberculosis strains previously unexposed to Rifacom EZ Kit (Ethambutol) have been uniformly sensitive to concentrations of 8 or less mcg/mL, depending on the nature of the culture media. When Rifacom EZ Kit (Ethambutol) has been used alone for treatment of tuberculosis, tubercle bacilli from these patients have developed resistance to Rifacom EZ Kit (Ethambutol) (ethambutol hydrochloride) by in-vitro susceptibility tests; the development of resistance has been unpredictable and appears to occur in a step-like manner. No cross resistance between Rifacom EZ Kit (Ethambutol) and other antituberculous drugs has been reported. Rifacom EZ Kit (Ethambutol) has reduced the incidence of the emergence of mycobacterial resistance to isoniazid when both drugs have been used concurrently.

An agar diffusion microbiologic assay, based upon inhibition of Mycobacterium smegmatis (ATCC 607) may be used to determine concentrations of Rifacom EZ Kit (Ethambutol) in serum and urine.

advertisement

ANIMAL PHARMACOLOGY

Toxicological studies in dogs on high prolonged doses produced evidence of myocardial damage and failure, and depigmentation of the tapetum lucidum of the eyes, the significance of which is not known. Degenerative changes in the central nervous system, apparently not dose-related, have also been noted in dogs receiving Rifacom EZ Kit (Ethambutol) hydrochloride over a prolonged period.

In the rhesus monkey, neurological signs appeared after treatment with high doses given daily over a period of several months. These were correlated with specific serum levels of Rifacom EZ Kit (Ethambutol) and with definite neuroanatomical changes in the central nervous system. Focal interstitial carditis was also noted in monkeys which received Rifacom EZ Kit (Ethambutol) hydrochloride in high doses for a prolonged period.

INDICATIONS AND USAGE

Rifacom EZ Kit (Ethambutol) is indicated for the treatment of pulmonary tuberculosis. It should not be used as the sole antituberculous drug, but should be used in conjunction with at least one other antituberculous drug. Selection of the companion drug should be based on clinical experience, considerations of comparative safety, and appropriate in-vitro susceptibility studies. In patients who have not received previous antituberculous therapy, ie, initial treatment, the most frequently used regimens have been the following:

Rifacom EZ Kit (Ethambutol) plus isoniazid

Rifacom EZ Kit (Ethambutol) plus isoniazid plus streptomycin.

In patients who have received previous antituberculous therapy, mycobacterial resistance to other drugs used in initial therapy is frequent. Consequently, in such retreatment patients, Rifacom EZ Kit (Ethambutol) should be combined with at least one of the second line drugs not previously administered to the patient and to which bacterial susceptibility has been indicated by appropriate in-vitro studies. Antituberculous drugs used with Rifacom EZ Kit (Ethambutol) have included cycloserine, ethionamide, pyrazinamide, viomycin and other drugs. Isoniazid, aminosalicylic acid, and streptomycin have also been used in multiple drug regimens. Alternating drug regimens have also been utilized.

advertisement

CONTRAINDICATIONS

Rifacom EZ Kit (Ethambutol) is contraindicated in patients who are known to be hypersensitive to this drug. It is also contraindicated in patients with known optic neuritis unless clinical judgment determines that it may be used. Rifacom EZ Kit (Ethambutol) is contraindicated in patients who are unable to appreciate and report visual side effects or changes in vision (e.g., young children, unconscious patients).

WARNINGS

Rifacom EZ Kit (Ethambutol) may produce decreases in visual acuity which appear to be due to optic neuritis. This effect may be related to dose and duration of treatment. This effect is generally reversible when administration of the drug is discontinued promptly. However, irreversible blindness has been reported. (See PRECAUTIONS and ADVERSE REACTIONS ).

Liver toxicities including fatalities have been reported. Baseline and periodic assessment of hepatic function should be performed.

PRECAUTIONS

Rifacom EZ Kit Rifacom EZ Kit (Ethambutol) hydrochloride is not recommended for use in pediatric patients under thirteen years of age since safe conditions for use have not been established.

Patients with decreased renal function need the dosage reduced as determined by serum levels of Rifacom EZ Kit (Ethambutol), since the main path of excretion of this drug is by the kidneys.

Because this drug may have adverse effects on vision, physical examination should include ophthalmoscopy, finger perimetry and testing of color discrimination. In patients with visual defects such as cataracts, recurrent inflammatory conditions of the eye, optic neuritis, and diabetic retinopathy, the evaluation of changes in visual acuity is more difficult, and care should be taken to be sure the variations in vision are not due to the underlying disease conditions. In such patients, consideration should be given to relationship between benefits expected and possible visual deterioration since evaluation of visual changes is difficult. (For recommended procedures, see next paragraphs under ADVERSE REACTIONS ).

As with any potent drug, baseline and periodic assessment of organ system functions, including renal, hepatic, and hematopoietic, should be performed.

Drug Interactions:

The results of a study of coadministration of Rifacom EZ Kit (Ethambutol) (50mg/kg) with an aluminum hydroxide containing antacid to 13 patients with tuberculosis showed a reduction of mean serum concentrations and urinary excretion of Rifacom EZ Kit (Ethambutol) of approximately 20% and 13%, respectively, suggesting that the oral absorption of Rifacom EZ Kit (Ethambutol) may be reduced by these antacid products. It is recommended to avoid concurrent administration of Rifacom EZ Kit (Ethambutol) with aluminum hydroxide containing antacids for at least 4 hours following Rifacom EZ Kit (Ethambutol) administration.

Pregnancy:

Teratogenic Effects: Pregnancy Category C.


There are no adequate and well-controlled studies in pregnant women. There are reports of ophthalmic abnormalities occurring in

infants born to women on antituberculous therapy that included Rifacom EZ Kit. Rifacom EZ Kit (Ethambutol) should be used during pregnancy

only if the benefit justifies the potential risk to the fetus.

Rifacom EZ Kit (Ethambutol) has been shown to be teratogenic in pregnant mice and rabbits when given in high doses. When pregnant mice or

rabbits were treated with high doses of Rifacom EZ Kit (Ethambutol) hydrochloride, fetal mortality was slightly but not significantly (P>0.05) increased.

Female rats treated with Rifacom EZ Kit (Ethambutol) hydrochloride displayed slight but insignificant (P>0.05) decreases in fertility and litter size.

In fetuses born of mice treated with high doses of Rifacom EZ Kit (Ethambutol) during pregnancy, a low incidence of cleft palate, exencephaly

and abnormality of the vertebral column were observed. Minor abnormalities of the cervical vertebra were seen in the newborn of

rats treated with high doses of Rifacom EZ Kit (Ethambutol) hydrochloride during pregnancy. Rabbits receiving high doses of Rifacom EZ Kit (Ethambutol) during

pregnancy gave birth to two fetuses with monophthalmia, one with a shortened right forearm accompanied by bilateral wrist-joint

contracture and one with hare lip and cleft palate.

Nursing Mothers:

Rifacom EZ Kit (Ethambutol) is excreted into breast milk. The use of Rifacom EZ Kit (Ethambutol) should be considered only if the expected benefit to the mother outweighs the potential risk to the infant.

Pediatric Use:

Rifacom EZ Kit (ethambutol hydrochloride) is not recommended for use in pediatric patients under thirteen years of age since safe conditions for use have not been established.

Geriatric Use:

There are limited data on the use of ethambutol in the elderly. One study of 101 patients, 65 years and older, on multiple drug antituberculosis regimens included 94 patients on Rifacom EZ Kit (Ethambutol). No differences in safety or tolerability were observed in these patients compared with that reported in adults in general. Other reported clinical experience has not identified differences in responses between the elderly and younger patients, but greater sensitivity of some older individuals cannot be ruled out.

advertisement

ADVERSE REACTIONS

Rifacom EZ Kit (Ethambutol) may produce decreases in visual acuity, including irreversible blindness, which appear to be due to optic neuritis. Optic neuropathy including optic neuritis or retrobulbar neuritis occurring in association with Rifacom EZ Kit (Ethambutol) therapy may be characterized by one or more of the following events: decreased visual acuity, scotoma, color blindness, and/or visual defect. These events have also been reported in the absence of a diagnosis of optic or retrobulbar neuritis.

Patients should be advised to report promptly to their physician any change of visual acuity.

The change in visual acuity may be unilateral or bilateral and hence each eye must be tested separately and both eyes tested together. Testing of visual acuity should be performed before beginning Rifacom EZ Kit (Ethambutol) therapy and periodically during drug administration, except that it should be done monthly when a patient is on a dosage of more than 15 mg per kilogram per day. Snellen eye charts are recommended for testing of visual acuity. Studies have shown that there are definite fluctuations of one or two lines of the Snellen chart in the visual acuity of many tuberculous patients not receiving Rifacom EZ Kit (Ethambutol).

The following table may be useful in interpreting possible changes in visual acuity attributable to Rifacom EZ Kit (Ethambutol).

Initial

Snellen

Reading

Reading Indicating

Significant Decrease

Significant

Number of Lines

Decrease

Number of Points

20/13 20/25 3 12
20/15 20/25 2 10
20/20 20/30 2 10
20/25 20/40 2 15
20/30 20/50 2 20
20/40 20/70 2 30
20/50 20/70 1 20

In general, changes in visual acuity less than those indicated under “Significant Number of Lines” and “Decrease Number of Points” may be due to chance variation, limitations of the testing method, or physiologic variability. Conversely, changes in visual acuity equaling or exceeding those under “Significant Number of Lines” and “Decrease Number of Points” indicate need for retesting and careful evaluation of the patient's visual status. If careful evaluation confirms the magnitude of visual change and fails to reveal another cause, Rifacom EZ Kit (Ethambutol) should be discontinued and the patient reevaluated at frequent intervals. Progressive decreases in visual acuity during therapy must be considered to be due to Rifacom EZ Kit (Ethambutol).

If corrective glasses are used prior to treatment, these must be worn during visual acuity testing. During 1 to 2 years of therapy, a refractive error may develop which must be corrected in order to obtain accurate test results. Testing the visual acuity through a pinhole eliminates refractive error. Patients developing visual abnormality during Rifacom EZ Kit (Ethambutol) treatment may show subjective visual symptoms before, or simultaneously with, the demonstration of decreases in visual acuity, and all patients receiving Rifacom EZ Kit (Ethambutol) should be questioned periodically about blurred vision and other subjective eye symptoms.

Recovery of visual acuity generally occurs over a period of weeks to months after the drug has been discontinued. Some patients have received Rifacom EZ Kit (Ethambutol) (ethambutol hydrochloride) again after such recovery without recurrence of loss of visual acuity.

Other adverse reactions reported include: hypersensitivity, anaphylactic/anaphylactoid reaction, dermatitis, erythema multiforme, pruritus, and joint pain; anorexia, nausea, vomiting, gastrointestinal upset, and abdominal pain; fever, malaise, headache, and dizziness; mental confusion, disorientation, and possible hallucinations; thrombocytopenia, leucopenia, and neutropenia. Numbness and tingling of the extremities due to peripheral neuritis have been reported.

Elevated serum uric acid levels occur and precipitation of acute gout has been reported. Pulmonary infiltrates, with or without eosinophilia, also have been reported during Rifacom EZ Kit (Ethambutol) therapy. Liver toxicities, including fatalities, have been reported (See WARNINGS. ) Since Rifacom EZ Kit (Ethambutol) is recommended for therapy in conjunction with one or more other antituberculous drugs, these changes may be related to the concurrent therapy. Hypersensitivity syndrome consisting ot cutaneous reaction (such as rash or exfoliative dermatitis), eosinophilia, and one or more of the following: hepatitis, pneumonitis, nephritis, myocarditis, pericarditis. Fever and lymphadenopathy may be present.

DOSAGE AND ADMINISTRATION

Rifacom EZ Kit should not be used alone, in initial treatment or in retreatment. Rifacom EZ Kit (Ethambutol) should be administered on a once every 24-hour basis only. Absorption is not significantly altered by administration with food. Therapy, in general, should be continued until bacteriological conversion has become permanent and maximal clinical improvement has occurred.

Rifacom EZ Kit (Ethambutol) is not recommended for use in pediatric patients under thirteen years of age since safe conditions for use have not been established.

Initial Treatment:

Initial Treatment:

In patients who have not received previous antituberculous therapy, administer Rifacom EZ Kit (Ethambutol) 15 mg/kg (7 mg/ lb) of body weight, as a single oral dose once every 24 hours. In the more recent studies, isoniazid has been administered concurrently in a single, daily, oral dose.

Retreatment:

Retreatment:

In patients who have received previous antituberculous therapy, administer Rifacom EZ Kit (Ethambutol) 25 mg/kg (11 mg/lb) of body weight, as a single oral dose once every 24 hours. Concurrently administer at least one other antituberculous drug to which the organisms have been demonstrated to be susceptible by appropriate in-vitro tests. Suitable drugs usually consist of those not previously used in the treatment of the patient. After 60 days of Rifacom EZ Kit (Ethambutol) administration, decrease the dose to 15 mg/kg (7mg/ lb) of body weight, and administer as a single oral dose once every 24 hours.

During the period when a patient is on a daily dose of 25 mg/kg, monthly eye examinations are advised.

See Table for easy selection of proper weight-dose tablet(s).

15 mg/kg (7 mg/lb) Schedule
Weight Range Daily Dose
Pounds Kilograms In mg
Under 85 lbs. Under 37 kg 500
85 - 94.5 37 – 43 600
95 - 109.5 43 – 50 700
110 - 124.5 50 – 57 800
125 - 139.5 57 – 64 900
140 - 154.5 64 – 71 1000
155 - 169.5 71 – 79 1100
170 - 184.5 79 – 84 1200
185 - 199.5 84 – 90 1300
200 - 214.5 90 – 97 1400
215 and Over Over 97 1500
25 mg/kg (11 mg/lb) Schedule
Under 85 lbs. Under 38 kg 900
85 - 92.5 38 - 42 1000
93 - 101.5 42 - 45.5 1100
102 - 109.5 45.5 – 50 1200
110 - 118.5 50 – 54 .1300
119 - 128.5 54 – 58 1400
129 - 136.5 58 – 62 1500
137 - 146.5 62 – 67 1600
147 - 155.5 67 – 71 1700
156 - 164.5 71 – 75 1800
165 - 173.5 75 – 79 1900
174 - 182.5 79 – 83 2000
183 - 191.5 83 – 87 2100
192 - 199.5 87 – 91 2200
200 - 209.5 91 – 95 2300
210 - 218.5 95 – 99 2400
219 and Over Over 99 2500

HOW SUPPLIED

Product: 50090-0417

NDC: 50090-0417-2 98 TABLET, FILM COATED in a BOTTLE

Rifacom EZ Kit (ETHAMBUTOL HYDROCHLORIDE) TABLET, FILM COATED

Isoniazid:


INDICATIONS AND USAGE

Rifacom EZ Kit (Isoniazid) is recommended for all forms of tuberculosis in which organisms are susceptible. However, active tuberculosis must be treated with multiple concomitant antituberculosis medications to prevent the emergence of drug resistance. Single-drug treatment of active tuberculosis with Rifacom EZ Kit (Isoniazid), or any other medication, is inadequate therapy.

Rifacom EZ Kit (Isoniazid) is recommended as preventive therapy for the following groups, regardless of age. (Note: the criterion for a positive reaction to a skin test (in millimeters of induration) for each group is given in parenthesis):

  • Persons with human immunodeficiency virus (HIV) infection (≥ 5 mm) and persons with risk factors for HIV infection whose HIV infection status is unknown but who are suspected of having HIV infection.

    Preventive therapy may be considered for HIV infected persons who are tuberculin-negative but belong to groups in which the prevalence of tuberculosis infection is high. Candidates for preventive therapy who have HIV infection should have a minimum of 12 months of therapy.

  • Close contacts of persons with newly diagnosed infectious tuberculosis (≥ 5 mm). In addition, tuberculin-negative (< 5 mm) children and adolescents who have been close contacts of infectious persons within the past 3 months are candidates for preventive therapy until a repeat tuberculin skin test is done 12 weeks after contact with the infectious source. If the repeat skin test is positive (> 5 mm), therapy should be continued.
  • Recent converters, as indicated by a tuberculin skin test (≥ 10 mm increase within a 2-year period for those < 35 years old; ≥ 15 mm increase for those ≥ 35 years of age). All infants and children younger than 4 years of age with a > 10 mm skin test are included in this category.
  • Persons with abnormal chest radiographs that show fibrotic lesions likely to represent old healed tuberculosis (≥ 5 mm). Candidates for preventive therapy who have fibrotic pulmonary lesions consistent with healed tuberculosis or who have pulmonary silicosis should have 12 months of Rifacom EZ Kit (Isoniazid) or 4 months of Rifacom EZ Kit (Isoniazid) and rifampin, concomitantly.
  • Intravenous drug users known to be HIV-seronegative (> 10 mm).
  • Persons with the following medical conditions that have been reported to increase the risk of tuberculosis (≥ 10 mm): silicosis; diabetes mellitus; prolonged therapy with adrenocorticosteroids; immunosuppressive therapy; some hematologic and reticuloendothelial diseases, such as leukemia or Hodgkin's disease; end-stage renal disease; clinical situations associated with substantial rapid weight loss or chronic undernutrition (including: intestinal bypass surgery for obesity, the postgastrectomy state (with or without weight loss), chronic peptic ulcer disease, chronic malabsorption syndromes, and carcinomas of the oropharynx and upper gastrointestinal tract that prevent adequate nutritional intake). Candidates for preventive therapy who have fibrotic pulmonary lesions consistent with healed tuberculosis or who have pulmonary silicosis should have 12 months of Rifacom EZ Kit (Isoniazid) or 4 months of Rifacom EZ Kit (Isoniazid) and rifampin, concomitantly.

Additionally, in the absence of any of the above risk factors, persons under the age of 35 with a tuberculin skin test reaction of 10 mm or more are also appropriate candidates for preventive therapy if they are a member of any of the following high-incidence groups:

  • Foreign-born persons from high-prevalence countries who never received BCG vaccine.
  • Medically underserved low-income populations, including high-risk racial or ethnic minority populations, especially blacks, Hispanics, and Native Americans.
  • Residents of facilities for long-term care (e.g., correctional institutions, nursing homes, and mental institutions).

Children who are less than 4 years old are candidates for Rifacom EZ Kit (Isoniazid) preventive therapy if they have >10 mm induration from a PPD Mantoux tuberculin skin test.

Finally, persons under the age of 35 who a) have none of the above risk factors (1-6); b) belong to none of the high-incidence groups; and c) have a tuberculin skin test reaction of 15 mm or more, are appropriate candidates for preventive therapy.

The risk of hepatitis must be weighed against the risk of tuberculosis in positive tuberculin reactors over the age of 35. However, the use of Rifacom EZ Kit (Isoniazid) is recommended for those with the additional risk factors listed above (1-6) and on an individual basis in situations where there is likelihood of serious consequences to contacts who may become infected.

advertisement

CONTRAINDICATIONS

Rifacom EZ Kit (Isoniazid) is contraindicated in patients who develop severe hypersensitivity reactions, including drug-induced hepatitis; previous isoniazid-associated hepatic injury; severe adverse reactions to Rifacom EZ Kit (Isoniazid) such as drug fever, chills, arthritis; and acute liver disease of any etiology.

WARNINGS

See the boxed WARNING .

PRECAUTIONS

General

All drugs should be stopped and an evaluation made at the first sign of a hypersensitivity reaction. If Rifacom EZ Kit therapy must be reinstituted, the drug should be given only after symptoms have cleared. The drug should be restarted in very small and gradually increasing doses and should be withdrawn immediately if there is any indication of recurrent hypersensitivity reaction.

Use of Rifacom EZ Kit (Isoniazid) should be carefully monitored in the following:

  • Daily users of alcohol. Daily ingestion of alcohol may be associated with a higher incidence of + Rifacom EZ Kit (Isoniazid) hepatitis.
  • Patients with active chronic liver disease or severe renal dysfunction.
  • Age > 35.
  • Concurrent use of any chronically administered medication.
  • History of previous discontinuation of Rifacom EZ Kit (Isoniazid).
  • Existence of peripheral neuropathy or conditions predisposing to neuropathy.
  • Pregnancy.
  • Injection drug use.
  • Women belonging to minority groups, particularly in the post-partum period.
  • HIV seropositive patients.

Laboratory Tests

Because there is a higher frequency of Rifacom EZ Kit (Isoniazid) associated hepatitis among certain patient groups, including Age > 35, daily users of alcohol, chronic liver disease, injection drug use and women belonging to minority groups, particularly in the post-partum period, transaminase measurements should be obtained prior to starting and monthly during preventative therapy, or more frequently as needed. If any of the values exceed three to five times the upper limit of normal, Rifacom EZ Kit (Isoniazid) should be temporarily discontinued and consideration given to restarting therapy.

Drug Interactions

Food

Rifacom EZ Kit should not be administered with food. Studies have shown that the bioavailability of Rifacom EZ Kit (Isoniazid) is reduced significantly when administered with food. Tyramine- and histamine-containing foods should be avoided in patients receiving Rifacom EZ Kit (Isoniazid). Because Rifacom EZ Kit (Isoniazid) has some monoamine oxidase inhibiting activity, an interaction with tyramine-containing foods (cheese, red wine) may occur. Diamine oxidase may also be inhibited, causing exaggerated response (e.g., headache, sweating, palpitations, flushing, hypotension) to foods containing histamine (e.g., skipjack, tuna, other tropical fish).

Acetaminophen

A report of severe acetaminophen toxicity was reported in a patient receiving Rifacom EZ Kit (Isoniazid). It is believed that the toxicity may have resulted from a previously unrecognized interaction between Rifacom EZ Kit (Isoniazid) and acetaminophen and a molecular basis for this interaction has been proposed. However, current evidence suggests that Rifacom EZ Kit (Isoniazid) does induce P-450IIE1, a mixed-function oxidase enzyme that appears to generate the toxic metabolites, in the liver. Furthermore it has been proposed that Rifacom EZ Kit (Isoniazid) resulted in induction of P-450IIE1 in the patients liver which, in turn, resulted in a greater proportion of the ingested acetaminophen being converted to the toxic metabolites. Studies have demonstrated that pretreatment with Rifacom EZ Kit (Isoniazid) potentiates acetaminophen hepatotoxicity in rats1,2.

Carbamazepine

Rifacom EZ Kit is known to slow the metabolism of carbamazepine and increase its serum levels. Carbamazepine levels should be determined prior to concurrent administration with Rifacom EZ Kit (Isoniazid), signs and symptoms of carbamazepine toxicity should be monitored closely, and appropriate dosage adjustment of the anticonvulsant should be made3.

Ketoconazole

Potential interaction of ketoconazole and Rifacom EZ Kit (Isoniazid) may exist. When ketoconazole is given in combination with Rifacom EZ Kit (Isoniazid) and rifampin the AUC of ketoconazole is decreased by as much as 88% after 5 months of concurrent Rifacom EZ Kit (Isoniazid) and rifampin therapy4.

Phenytoin

Rifacom EZ Kit may increase serum levels of phenytoin. To avoid phenytoin intoxication, appropriate adjustment of the anticonvulsant should be made5,6.

Theophylline

A recent study has shown that concomitant administration of Rifacom EZ Kit (Isoniazid) and theophylline may cause elevated plasma levels of theophylline, and in some instances a slight decrease in the elimination of Rifacom EZ Kit (Isoniazid). Since the therapeutic range of theophylline is narrow, theophylline serum levels should be monitored closely, and appropriate dosage adjustments of theophylline should be made7.

Valproate

A recent case study has shown a possible increase in the plasma level of valproate when co-administered with Rifacom EZ Kit. Plasma valproate concentration should be monitored when Rifacom EZ Kit (Isoniazid) and valproate are co-administered, and appropriate dosage adjustments of valproate should be made8.

Carcinogenesis and Mutagenesis:

Rifacom EZ Kit (Isoniazid) has been shown to induce pulmonary tumors in a number of strains of mice. Rifacom EZ Kit (Isoniazid) has not been shown to be carcinogenic in humans. (Note: a diagnosis of mesothelioma in a child with prenatal exposure to Rifacom EZ Kit (Isoniazid) and no other apparent risk factors has been reported). Rifacom EZ Kit (Isoniazid) has been found to be weakly mutagenic in strains TA 100 and TA 1535 of Salmonella typhimurium (Ames assay) without metabolic activation.

Pregnancy

Teratogenic effects: Pregnancy Category C

Rifacom EZ Kit has been shown to have an embryocidal effect in rats and rabbits when given orally during pregnancy. Rifacom EZ Kit (Isoniazid) was not teratogenic in reproduction studies in mice, rats and rabbits. There are no adequate and well-controlled studies in pregnant women. Rifacom EZ Kit (Isoniazid) should be used as a treatment for active tuberculosis during pregnancy because the benefit justifies the potential risk to the fetus. The benefit of preventive therapy also should be weighed against a possible risk to the fetus. Preventive therapy generally should be started after delivery to prevent putting the fetus at risk of exposure; the low levels of Rifacom EZ Kit (Isoniazid) in breast milk do not threaten the neonate. Since Rifacom EZ Kit (Isoniazid) is known to cross the placental barrier, neonates of Rifacom EZ Kit (Isoniazid) treated mothers should be carefully observed for any evidence of adverse affects.

Nonteratogenic effects

Since Rifacom EZ Kit (Isoniazid) is known to cross the placental barrier, neonates of isoniazid-treated mothers should be carefully observed for any evidence of adverse effects.

Nursing Mothers

The small concentrations of Rifacom EZ Kit (Isoniazid) in breast milk do not produce toxicity in the nursing newborn; therefore, breast feeding should not be discouraged. However, because levels of Rifacom EZ Kit (Isoniazid) are so low in breast milk, they can not be relied upon for prophylaxis or therapy of nursing infants.

ADVERSE REACTIONS

The most frequent reactions are those affecting the nervous system and the liver.

Nervous System Reactions - Peripheral neuropathy is the most common toxic effect. It is dose-related, occurs most often in the malnourished and in those predisposed to neuritis (e.g., alcoholics and diabetics), and is usually preceded by paresthesias of the feet and hands. The incidence is higher in "slow inactivators".

Other neurotoxic effects, which are uncommon with conventional doses, are convulsions, toxic encephalopathy, optic neuritis and atrophy, memory impairment, and toxic psychosis.

Hepatic Reactions - See boxed WARNING. Elevated serum transaminase (SGOT; SGPT), bilirubinemia, bilirubinuria, jaundice, and occasionally severe and sometimes fatal hepatitis. The common prodromal symptoms of hepatitis are anorexia, nausea, vomiting, fatigue, malaise, and weakness. Mild hepatic dysfunction, evidenced by mild and transient elevation of serum transaminase levels occurs in 10% to 20% of patients taking Rifacom EZ Kit (Isoniazid). This abnormality usually appears in the first 1 to 3 months of treatment but can occur at any time during therapy. In most instances, enzyme levels return to normal, and generally, there is no necessity to discontinue medication during the period of mild serum transaminase elevation. In occasional instances, progressive liver damage occurs, with accompanying symptoms. If the SGOT value exceeds three to five times the upper limit of normal, discontinuation of the Rifacom EZ Kit (Isoniazid) should be strongly considered. The frequency of progressive liver damage increases with age. It is rare in persons under 20, but occurs in up to 2.3 percent of those over 50 years of age.

Gastrointestinal Reactions - Nausea, vomiting, and epigastric distress.

Hematologic Reactions - Agranulocytosis; hemolytic, sideroblastic, or aplastic anemia, thrombocytopenia; and eosinophilia.

Hypersensitivity Reactions - Fever, skin eruptions (morbilliform, maculopapular, purpuric, or exfoliative), lymphadenopathy, and vasculitis.

Metabolic and Endocrine Reactions - Pyridoxine deficiency, pellagra, hyperglycemia, metabolic acidosis, and gynecomastia.

Miscellaneous Reactions - Rheumatic syndrome and systemic lupus erythematosus-like syndrome.

To report SUSPECTED ADVERSE REACTIONS, contact West-ward Pharmaceutical Corp. at 1-877-233-2001, and the FDA at 1-800-FDA-1088 or www.fda.gov/medwatch.

OVERDOSAGE

Signs and Symptoms

Rifacom EZ Kit overdosage produces signs and symptoms within 30 minutes to 3 hours after ingestion. Nausea, vomiting, dizziness, slurring of speech, blurring of vision, and visual hallucinations (including bright colors and strange designs) are among the early manifestations. With marked overdosage, respiratory distress and CNS depression, progressing rapidly from stupor to profound coma, are to be expected, along with severe, intractable seizures. Severe metabolic acidosis, acetonuria, and hyperglycemia are typical laboratory findings.

Treatment

Untreated or inadequately treated cases of gross Rifacom EZ Kit (Isoniazid) overdosage, 80 mg/kg - 150 mg/kg, can cause neurotoxicity6 and terminate fatally, but good response has been reported in most patients brought under adequate treatment within the first few hours after drug ingestion.

For the Asymptomatic Patient

Absorption of drugs from the GI tract may be decreased by giving activated charcoal. Gastric emptying should also be employed in the asymptomatic patient. Safeguard the patient"s airway when employing these procedures. Patients who acutely ingest > 80 mg/kg should be treated with intravenous pyridoxine on a gram per gram basis equal to the Rifacom EZ Kit dose. If an unknown amount of Rifacom EZ Kit (Isoniazid) is ingested, consider an initial dose of 5 grams of pyridoxine given over 30 to 60 minutes in adults, or 80 mg/kg of pyridoxine in children.

For the Symptomatic Patient

Ensure adequate ventilation, support cardiac output, and protect the airway while treating seizures and attempting to limit absorption. If the dose of Rifacom EZ Kit (Isoniazid) is known, the patient should be treated initially with a slow intravenous bolus of pyridoxine, over 3 to 5 minutes, on a gram per gram basis, equal to the Rifacom EZ Kit (Isoniazid) dose. If the quantity of Rifacom EZ Kit (Isoniazid) ingestion is unknown, then consider an initial intravenous bolus of pyridoxine of 5 grams in the adult or 80 mg/kg in the child. If seizures continue, the dosage of pyridoxine may be repeated. It would be rare that more than 10 grams of pyridoxine would need to be given. The maximum safe dose for pyridoxine in Rifacom EZ Kit (Isoniazid) intoxication is not known. If the patient does not respond to pyridoxine, diazepam may be administered. Phenytoin should be used cautiously, because Rifacom EZ Kit (Isoniazid) interferes with the metabolism of phenytoin.

General

Obtain blood samples for immediate determination of gases, electrolytes, BUN, glucose, etc.; type and cross-match blood in preparation for possible hemodialysis.

Rapid control of metabolic acidosis

Patients with this degree of INH intoxication are likely to have hypoventilation. The administration of sodium bicarbonate under these circumstances can cause exacerbation of hypercarbia. Ventilation must be monitored carefully, by measuring blood carbon dioxide levels, and supported mechanically, if there is respiratory insufficiency.

Dialysis

Both peritoneal and hemodialysis have been used in the management of Rifacom EZ Kit (Isoniazid) overdosage. These procedures are probably not required if control of seizures and acidosis is achieved with pyridoxine, diazepam and bicarbonate.

Along with measures based on initial and repeated determination of blood gases and other laboratory tests as needed, utilize meticulous respiratory and other intensive care to protect against hypoxia, hypotension, aspiration, pneumonitis, etc.

DOSAGE AND ADMINISTRATION

: NOTE: For preventive therapy of tuberculous infection and treatment of tuberculosis, it is recommended that physicians be familiar with the following publications: (1) the recommendations of the Advisory Council for the Elimination of Tuberculosis, published in the MMWR: vol 42; RR-4, 1993 and (2) Treatment of Tuberculosis and Tuberculosis Infection in Adults and Children, American Journal of Respiratory and Critical Care Medicine: vol 149; 1359-1374, 1994.

For Treatment of Tuberculosis - Rifacom EZ Kit (Isoniazid) is used in conjunction with other effective anti-tuberculosis agents. Drug susceptibility testing should be performed on the organisms initially isolated from all patients with newly diagnosed tuberculosis. If the bacilli become resistant, therapy must be changed to agents to which the bacilli are susceptible.

Usual Oral Dosage (depending on the regimen used):

  • Adults: 5 mg/kg up to 300 mg daily in a single dose; or

    15 mg/kg up to 900 mg day, two or three times/week

  • Children: 10-15 mg/kg up to 300 mg daily in a single dose; or

    20-40 mg/kg up to 900 mg/day, two or three time/week

Patients with Pulmonary Tuberculosis Without HIV Infection

There are 3 regimen options for the initial treatment of tuberculosis in children and adults:

Option 1: Daily Rifacom EZ Kit (Isoniazid), rifampin, and pyrazinamide for 8 weeks followed by 16 weeks of Rifacom EZ Kit (Isoniazid) and rifampin daily or 2-3 times weekly. Ethambutol or streptomycin should be added to the initial regimen until sensitivity to Rifacom EZ Kit (Isoniazid) and rifampin is demonstrated. The addition of a fourth drug is optional if the relative prevalence of isoniazid-resistant Mycobacterium tuberculosis isolates in the community is less than or equal to four percent.

Option 2: Daily Rifacom EZ Kit (Isoniazid), rifampin, pyrazinamide, and streptomycin or ethambutol for 2 weeks followed by twice weekly administration of the same drugs for 6 weeks, subsequently twice weekly Rifacom EZ Kit (Isoniazid) and rifampin for 16 weeks.

Option 3: Three times weekly with Rifacom EZ Kit (Isoniazid), rifampin, pyrazinamide, and ethambutol or streptomycin for 6 months.

*All regimens given twice weekly or 3 times weekly should be administered by directly observed therapy.

The above treatment guidelines apply only when the disease is caused by organisms that are susceptible to the standard antituberculous agents. Because of the impact of resistance to Rifacom EZ Kit (Isoniazid) and rifampin on the response to therapy, it is essential that physicians initiating therapy for tuberculosis be familiar with the prevalence of drug resistance in their communities. It is suggested that ethambutol not be used in children whose visual acuity cannot be monitored.

Patients with Pulmonary Tuberculosis and HIV Infection

The response of the immunologically impaired host to treatment may not be as satisfactory as that of a person with normal host responsiveness. For this reason, therapeutic decisions for the impaired host must be individualized. Since patients co-infected with HIV may have problems with malabsorption, screening of antimycobacterial drug levels, especially in patients with advanced HIV disease, may be necessary to prevent the emergence of MDRTB.

Patients with Extra pulmonary Tuberculosis

The basic principles that underlie the treatment of pulmonary tuberculosis also apply to Extra pulmonary forms of the disease. Although there have not been the same kinds of carefully conducted controlled trials of treatment of Extra pulmonary tuberculosis as for pulmonary disease, increasing clinical experience indicates that a 6 to 9 month short-course regimen is effective. Because of the insufficient data, miliary tuberculosis, bone/joint tuberculosis, and tuberculous meningitis in infants and children should receive 12 months therapy.

Bacteriologic evaluation of Extra pulmonary tuberculosis may be limited by the relative inaccessibility of the sites of disease. Thus, response to treatment often must be judged on the basis of clinical and radiographic findings.

The use of adjunctive therapies such as surgery and corticosteroids is more commonly required in Extra pulmonary tuberculosis than in pulmonary disease. Surgery may be necessary to obtain specimens for diagnosis and to treat such processes as constrictive pericarditis and spinal cord compression from Pott's Disease. Corticosteriods have been shown to be of benefit in preventing cardiac constriction from tuberculous pericarditis and in decreasing the neurologic sequelae of all stages of tuberculosis meningitis, especially when administered early in the course of the disease.

Pregnant Women with Tuberculosis

The options listed above must be adjusted for the pregnant patient. Streptomycin interferes with in utero development of the ear and may cause congenital deafness. Routine use of pyrazinamide is also not recommended in pregnancy because of inadequate teratogenicity data. The initial treatment regimen should consist of Rifacom EZ Kit and rifampin. Ethambutol should be included unless primary Rifacom EZ Kit (Isoniazid) resistance is unlikely (isoniazid resistance rate documented to be less than 4%).

Treatment of Patients with Multi-Drug Resistant Tuberculosis (MDRTB)

Multiple-drug resistant tuberculosis (i.e., resistance to at least Rifacom EZ Kit (Isoniazid) and rifampin) presents difficult treatment problems. Treatment must be individualized and based on susceptibility studies. In such cases, consultation with an expert in tuberculosis is recommended.

Directly Observed Therapy

A major cause of drug-resistant tuberculosis is patient non-compliance with treatment. The use of DOT can help assure patient compliance with drug therapy. DOT is the observation of the patient by a health care provider or other responsible person as the patient ingests anti-tuberculosis medications. DOT can be achieved with daily, twice weekly or thrice weekly regimens, and is recommended for all patients.

For Preventative Therapy of Tuberculosis

Before Rifacom EZ Kit (Isoniazid) preventive therapy is initiated, bacteriologically positive or radiographically progressive tuberculosis must be excluded. Appropriate evaluations should be performed if Extra pulmonary tuberculosis is suspected.

Adults over 30 Kg: 300 mg per day in a single dose.

Infants and Children: 10 mg/kg (up to 300 mg daily) in a single dose. In situations where adherence with daily preventative therapy cannot be assured, 20-30 mg/kg (not to exceed 900 mg) twice weekly under the direct observation of a health care worker at the time of administration8.

Continuous administration of Rifacom EZ Kit (Isoniazid) for a sufficient period is an essential part of the regimen because relapse rates are higher if chemotherapy is stopped prematurely. In the treatment of tuberculosis, resistant organisms may multiply and the emergence of resistant organisms during the treatment may necessitate a change in the regimen.

For following patient compliance: the Potts-Cozart test9, a simple colorimetric6 method of checking for Rifacom EZ Kit (Isoniazid) in the urine, is a useful tool for assuring patient compliance, which is essential for effective tuberculosis control. Additionally, Rifacom EZ Kit (Isoniazid) test strips are also available to check patient compliance.

Concomitant administration of pyridoxine (B6) is recommended in the malnourished and in those predisposed to neuropathy (e.g., alcoholics and diabetics).

HOW SUPPLIED

Rifacom EZ Kit (Isoniazid) Tablets, USP 100 mg: White, Round Tablets; Debossed "West-ward" on one side and "260" on the Scored side.

  • Bottles of 100 tablets
  • Bottles of 1000 tablets
  • Unit Dose Boxes of 100 tablets

Rifacom EZ Kit (Isoniazid) Tablets, USP 300 mg: White, Round Tablets; Debossed "West-ward 261" on one side and Scored on the other side.

  • Bottles of 30 tablets
  • Bottles of 100 tablets
  • Bottles of 1000 tablets
  • Unit Dose Boxes of 100 tablets

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.

References

  • Murphy, R., et al: Annuals of Internal Medicine; 1990: November 15; volume 113:799-800.
  • Burke, R.F., et al: Res Commun Chem Pathol Pharmacol. 1990;J uly; vol. 69; 115-118.
  • Fleenor, M.F., et al: Chest (United States) Letter; 1991: June; 99(6): 1554.
  • Baciewicz, A.M. and Baciewicz,Jr. F.A.,: Arch Int Med 1993, September; volume 153;1970-1971.
  • Jonville, A.P., et al: European Journal of Clinical Pharmacol (Germany), 1991: 40(2) p198.
  • American Thoracic Society/Centers for Disease Control: Treatment of Tuberculosis and Tuberculosis Infection in

    Adults and Children. Amer. J. Respir Crit Care Med.1994; 149: p 1359-1374.

  • Hoglund P.,et al: European Journal of Respir Dis (Denmark) 1987: February; 70(2) p110-116.
  • Committee on Infectious Diseases American Academy of Pediatrics: 1994, Red Book: Report of the

    Committee on Infectious Diseases; 23rd edition; p487.

  • Schraufnagel, DE; Testing for Rifacom EZ Kit (Isoniazid); Chest (United States) 1990, August: 98(2) p314-316.

Manufactured by:

West-ward Pharmaceutical Corp.

Eatontown, NJ 07724

Revised February 2011

Rifacom EZ Kit (Isoniazid) 300mg Tablet

Structural Formula

Pyrazinamide:


INDICATIONS AND USAGE:

Rifacom EZ Kit (Pyrazinamide) is indicated for the initial treatment of active tuberculosis in adults and children when combined with other antituberculous agents. (The current recommendation of the CDC for drug-susceptible disease is to use a six-month regimen for initial treatment of active tuberculosis, consisting of isoniazid, rifampin and Rifacom EZ Kit (Pyrazinamide) given for 2 months, followed by isoniazid and rifampin for 4 months.*4)

(Patients with drug-resistant disease should be treated with regimens individualized to their situation. Rifacom EZ Kit (Pyrazinamide) frequently will be an important component of such therapy.)

(In patients with concomitant HIV infection, the physician should be aware of current recommendation of CDC. It is possible these patients may require a longer course of treatment).

It is also indicated after treatment failure with other primary drugs in any form of active tuberculosis.

Rifacom EZ Kit (Pyrazinamide) should only be used in conjunction with other effective antituberculous agents.

*See recommendations of Center for Disease Control (CDC) and American Thoracic Society for complete regimen and dosage recommendations.4

CONTRAINDICATIONS:

Rifacom EZ Kit (Pyrazinamide) is contraindicated in persons:

  • with severe hepatic damage.
  • who have shown hypersensitivity to it.
  • with acute gout.

WARNINGS:

Patients started on Rifacom EZ Kit (Pyrazinamide) should have baseline serum uric acid and liver function determinations. Those patients with preexisting liver disease or those at increased risk for drug related hepatitis (e.g., alcohol abusers) should be followed closely.

Rifacom EZ Kit (Pyrazinamide) should be discontinued and not be resumed if signs of hepatocellular damage or hyperuricemia accompanied by an acute gouty arthritis appear.

PRECAUTIONS:

General:

Rifacom EZ Kit inhibits renal excretion of urates, frequently resulting in hyperuricemia which is usually asymptomatic. If hyperuricemia is accompanied by acute gouty arthritis, Rifacom EZ Kit (Pyrazinamide) should be discontinued.

Rifacom EZ Kit (Pyrazinamide) should be used with caution in patients with a history of diabetes mellitus, as management may be more difficult.

Primary resistance of M. tuberculosis to Rifacom EZ Kit (Pyrazinamide) is uncommon. In cases with known or suspected drug resistance, in vitro susceptibility tests with recent cultures of M. tuberculosis against Rifacom EZ Kit (Pyrazinamide) and the usual primary drugs should be performed. There are few reliable in vitro tests for Rifacom EZ Kit (Pyrazinamide) resistance. A reference laboratory capable of performing these studies must be employed.

Information for Patients:

Patients should be instructed to notify their physicians promptly if they experience any of the following: fever, loss of appetite, malaise, nausea and vomiting, darkened urine, yellowish discoloration of the skin and eyes, pain or swelling of the joints.

Compliance with the full course of therapy must be emphasized, and the importance of not missing any doses must be stressed.

Laboratory Tests:

Baseline liver function studies [especially ALT, AST (SGOT) determinations] and uric acid levels should be determined prior to therapy. Appropriate laboratory testing should be performed at periodic intervals and if any clinical signs of symptoms occur during therapy.

Drug/Laboratory Test Interactions:

Rifacom EZ Kit (Pyrazinamide) has been reported to interfere with ACETEST® and KETOSTIX® urine tests to produce a pink-brown color.5

Carcinogenesis, Mutagenesis, Impairment of Fertility:6,7,8

In lifetime bioassays in rats and mice, Rifacom EZ Kit was administered in the diet at concentrations of up to 10,000 ppm. This resulted in estimated daily doses for the mouse of 2 g/kg, or 40 times the maximum human dose, and for the rat of 0.5 g/kg, or 10 times the maximum human dose. Rifacom EZ Kit (Pyrazinamide) was not carcinogenic in rats or male mice and no conclusion was possible for female mice due to insufficient numbers of surviving control mice.

Rifacom EZ Kit (Pyrazinamide) was not mutagenic in the Ames bacterial test, but induced chromosomal aberrations in human lymphocyte cell cultures.

Pregnancy:

Teratogenic Effects-Pregnancy Category C

Animal reproduction studies have not been conducted with Rifacom EZ Kit. It is also not known whether Rifacom EZ Kit (Pyrazinamide) can cause fetal harm when administered to a pregnant woman or can affect reproduction capacity. Rifacom EZ Kit (Pyrazinamide) should be given to a pregnant woman only if clearly needed.

Nursing Mothers:

Rifacom EZ Kit (Pyrazinamide) has been found in small amounts in breast milk. Therefore, it is advised that Rifacom EZ Kit (Pyrazinamide) be used with caution in nursing mothers taking into account the risk-benefit of this therapy.9

Pediatric Use:

Rifacom EZ Kit regimens employed in adults are probably equally effective in pediatric patients.4,10,11 Rifacom EZ Kit (Pyrazinamide) appears to be well tolerated in pediatric patients.

Geriatric Use:12

Clinical studies of Rifacom EZ Kit (Pyrazinamide) did not include sufficient numbers of patients aged 65 and over to determine whether they respond differently from younger patients. Other reported clinical experience has not identified differences in responses between the elderly and younger patients. In general, dose selection for an elderly patient should be cautious, usually starting at the low end of the dosing range, reflecting the greater frequency of decreased hepatic or renal function, and of concomitant disease or other drug therapy.

It does not appear that patients with impaired renal function require a reduction in dose. It may be prudent to select doses at the low end of the dosing range, however.13

ADVERSE REACTIONS:

General:

Fever, porphyria and dysuria have rarely been reported. Gout.

Gastrointestinal:

The principal adverse effect is a hepatic reaction. Hepatotoxicity appears to be dose related, and may appear at any time during therapy. GI disturbances including nausea, vomiting and anorexia have also been reported.

Hematologic and Lymphatic:

Thrombocytopenia and sideroblastic anemia with erythroid hyperplasia, vacuolation of erythrocytes and increased serum iron concentration have occurred rarely with this drug. Adverse effects on blood clotting mechanisms have also been rarely reported.

Other:

Mild arthralgia and myalgia have been reported frequently. Hypersensitivity reactions including rashes, urticaria, and pruritis have been reported. Fever, acne, photosensitivity, porphyria, dysuria and interstitial nephritis have been reported rarely.

OVERDOSAGE:

Overdosage experience is limited. In one case report of overdose, abnormal liver function tests developed. These spontaneously reverted to normal when the drug was stopped. Clinical monitoring and supportive therapy should be employed. Rifacom EZ Kit (Pyrazinamide) is dialyzable.13

DOSAGE AND ADMINISTRATION:

Rifacom EZ Kit (Pyrazinamide) should always be administered with other effective antituberculous drugs. It is administered for the initial 2 months of a 6-month or longer treatment regimen for drug-susceptible patients. Patients who are known or suspected to have drug-resistant disease should be treated with regimens individualized to their situation.

Rifacom EZ Kit (Pyrazinamide) frequently will be an important component of such therapy.

Patients with concomitant HIV infection may require longer courses of therapy. Physicians treating such patients should be alert to any revised recommendations from CDC for this group of patients.

Usual dose: Rifacom EZ Kit (Pyrazinamide) is administered orally, 15 to 30 mg/kg once daily. Older regimens employed 3 or 4 divided doses daily, but most current recommendations are for once a day. Three grams per day should not be exceeded. The CDC recommendations do not exceed 2 g per day when given as a daily regimen.

Alternatively, a twice weekly dosing regimen (50 to 75 mg/kg twice weekly based on lean body weight) has been developed to promote patient compliance with a regimen on an outpatient basis. In studies evaluation the twice weekly regimen, doses of Rifacom EZ Kit (Pyrazinamide) in excess of 3 g twice weekly have been administered. This exceeds the recommended maximum 3 g/daily dose. However, an increased incidence of adverse reactions has not been reported.

This table is taken from the CDC-American Thoracic Society joint recommendations.4

Daily Dose Doses based on weight should be adjusted as weight changes.
Drug Children Adults
Isoniazid

10 to 20 mg/kg

PO or IM


5 mg/kg

PO or IM

Rifampin

10 to 20 mg/kg

PO


10 mg/kg

PO

Rifacom EZ Kit (Pyrazinamide)

15 to 30 mg/kg

PO


15 to 30 mg/kg

PO

Streptomycin

20 to 40 mg/kg

IM


15 mg/kgIn persons older than 60 yr of age the daily dose of streptomycin should be limited to 10 mg/kg with a maximal dose of 750 mg.

IM

Ethambutol

15 to 25 mg/kg

PO


15 to 25 mg/kg

PO

Maximal Daily Dose in Children and Adults
Drug
Isoniazid 300 mg
Rifampin 600 mg
Rifacom EZ Kit (Pyrazinamide) 2 g
Streptomycin 1 gIn persons older than 60 yr of age the daily dose of streptomycin should be limited to 10 mg/kg with a maximal dose of 750 mg.
Ethambutol 2.5 g
Twice Weekly Dose
Drug Children Adults
Isoniazid

20 to 40 mg/kg

Max. 900 mg


15 mg/kg

Max. 900 mg

Rifampin

10 to 20 mg/kg

Max. 600 mg


10 mg/kg

Max. 600 mg

Rifacom EZ Kit (Pyrazinamide) 50 to 70 mg/kg 50 to 70 mg/kg
Streptomycin

25 to 30 mg/kg

IM


25 to 30 mg/kg

IM

Ethambutol 50 mg/kg 50 mg/kg

Definition of abbreviations: PO = per-orally; IM = intramuscularly.

HOW SUPPLIED:

Product: 50090-0520

NDC: 50090-0520-0 100 TABLET in a CONTAINER

REFERENCES:

1.Drug Information, American Hospital Formulary Service. American Society of Hospital Pharmacists. Bethesda, Md. 1991.

2. USPDI, Drug Information for the Health Care Professional. United States Pharmacopeial Convention, Inc. Rockville, Md. 1991: 1 B : 2226-2227.

3. Goodman-Gilman A, Rall TW, Nies AS, Taylor P. The Pharmacological Basis of Therapeutics, ed 8. New York, Pergamon Press. 1990; 1154.

4. Treatment of tuberculosis and tuberculosis infection in adults and children. Am Rev Respir Dis. 1986 ; 134 : 363-368.

5. Reynolds JEF, Parfitt K, Parsons AV, Sweetman SC. Martindale The Extra Pharmacopoeia, ed 29. London, The Pharmaceutical Press. 1989; 569-570.

6. Bioassay of Rifacom EZ Kit (Pyrazinamide) for possible carcinogenicity. National Cancer Institute Carcinogenesis Technical Report Series No. 48, 1978.

7. Zerger E, Anderson B, Haworth S, Lawlor T, Mortelmans K, Speck W. Salmonella mutagenicity tests: III. Results from the testing of 255 chemicals. Environ Mutagen. 1987; 9 (Suppl 9) : 1109.

8. Roman IC, Georgian L. Cytogenetic effects of some antituberculosis drugs in vitro. Mutation Research. 1977; 48: 215- 224.

9. Holdiness M. Antituberculosis drugs and breast-feeding. Arch Intern Med. 1984; 144: 1888.

10. Turcios N, Evans H. Preventing and managing tuberculosis in children. J Resp Dis. 1989; 10 (6) (Jun): 23.

11. Starke JR. Multidrug therapy for tuberculosis in children. Pediatr Infec Dis J. 1990; 9: 785793.

12. Specific requirements on content and format of labeling for human prescription drugs; proposed addition of "geriatric use" subsection in the labeling. Federal Register. 1990; 55 (212) (Nov 1): 46134-46137.

13. Stamathakis G, Montes C, Trouvin JH, et al. Rifacom EZ Kit (Pyrazinamide) and pyrazinoic acid pharmacokinetics in patients with chronic renal failure. Clinical Nephrology. 1988 ; 30 : 230-234.

Rifacom EZ Kit

Rifampin:


INDICATIONS AND USAGE

In the treatment of both tuberculosis and the meningococcal carrier state, the small number of resistant cells present within large populations of susceptible cells can rapidly become the predominant type. Bacteriologic cultures should be obtained before the start of therapy to confirm the susceptibility of the organism to Rifacom EZ Kit and they should be repeated throughout therapy to monitor the response to treatment. Since resistance can emerge rapidly, susceptibility tests should be performed in the event of persistent positive cultures during the course of treatment. If test results show resistance to Rifacom EZ Kit (Rifampin) and the patient is not responding to therapy, the drug regimen should be modified.

Tuberculosis

Rifacom EZ Kit (Rifampin) is indicated in the treatment of all forms of tuberculosis.

A three-drug regimen consisting of Rifacom EZ Kit (Rifampin), isoniazid, and pyrazinamide (e.g., RIFATER® manufactured by Sanofi Aventis) is recommended in the initial phase of short-course therapy which is usually continued for 2 months. The Advisory Council for the Elimination of Tuberculosis, the American Thoracic Society, and Centers for Disease Control and Prevention recommend that either streptomycin or ethambutol be added as a fourth drug in a regimen containing isoniazid (INH), Rifacom EZ Kit (Rifampin), and pyrazinamide for initial treatment of tuberculosis unless the likelihood of INH resistance is very low. The need for a fourth drug should be reassessed when the results of susceptibility testing are known. If community rates of INH resistance are currently less than 4%, an initial treatment regimen with less than four drugs may be considered.

Following the initial phase, treatment should be continued with Rifacom EZ Kit (Rifampin) and isoniazid (e.g., RIFAMATE® manufactured by Sanofi Aventis) for at least 4 months. Treatment should be continued for longer if the patient is still sputum or culture positive, if resistant organisms are present, or if the patient is HIV positive.

Rifacom EZ Kit (Rifampin) for injection is indicated for the initial treatment and retreatment of tuberculosis when the drug cannot be taken by mouth.

Meningococcal Carriers

Rifacom EZ Kit (Rifampin) is indicated for the treatment of asymptomatic carriers of Neisseria meningitidis to eliminate meningococci from the nasopharynx. Rifacom EZ Kit (Rifampin) is not indicated for the treatment of meningococcal infection because of the possibility of the rapid emergence of resistant organisms. (See WARNINGS .)

Rifacom EZ Kit (Rifampin) should not be used indiscriminately, and therefore, diagnostic laboratory procedures, including serotyping and susceptibility testing, should be performed for establishment of the carrier state and the correct treatment. So that the usefulness of Rifacom EZ Kit (Rifampin) in the treatment of asymptomatic meningococcal carriers is preserved, the drug should be used only when the risk of meningococcal disease is high.

To reduce the development of drug-resistant bacteria and maintain the effectiveness of Rifacom EZ Kit (Rifampin) and other antibacterial drugs, Rifacom EZ Kit (Rifampin) should be used only to treat or prevent infections that are proven or strongly suspected to be caused by susceptible bacteria. When culture and susceptibility information are available, they should be considered in selecting or modifying antibacterial therapy. In the absence of such data, local epidemiology and susceptibility patterns may contribute to the empiric selection of therapy.

CONTRAINDICATIONS

Rifacom EZ Kit (Rifampin) is contraindicated in patients with a history of hypersensitivity to Rifacom EZ Kit (Rifampin) or any of the components, or to any of the rifamycins. (See WARNINGS .)

Rifacom EZ Kit (Rifampin) is contraindicated in patients who are also receiving ritonavir-boosted saquinavir due to an increased risk of severe hepatocellular toxicity. (See PRECAUTIONS, Drug Interactions .) Rifacom EZ Kit (Rifampin) is contraindicated in patients who are also receiving atazanavir, darunavir, fosamprenavir, saquinavir, or tipranavir due to the potential of Rifacom EZ Kit (Rifampin) to substantially decrease plasma concentrations of these antiviral drugs, which may result in loss of antiviral efficacy and/or development of viral resistance.

WARNINGS

Rifacom EZ Kit (Rifampin) has been shown to produce liver dysfunction. Fatalities associated with jaundice have occurred in patients with liver disease and in patients taking Rifacom EZ Kit (Rifampin) with other hepatotoxic agents. Patients with impaired liver function should be given Rifacom EZ Kit (Rifampin) only in cases of necessity and then with caution and under strict medical supervision. In these patients, careful monitoring of liver function, especially SGPT/ALT and SGOT/AST should be carried out prior to therapy and then every 2 to 4 weeks during therapy. If signs of hepatocellular damage occur, Rifacom EZ Kit (Rifampin) should be withdrawn.

In some cases, hyperbilirubinemia resulting from competition between Rifacom EZ Kit (Rifampin) and bilirubin for excretory pathways of the liver at the cell level can occur in the early days of treatment. An isolated report showing a moderate rise in bilirubin and/or transaminase level is not in itself an indication for interrupting treatment; rather, the decision should be made after repeating the tests, noting trends in the levels, and considering them in conjunction with the patient's clinical condition.

Rifacom EZ Kit (Rifampin) has enzyme-inducing properties, including induction of delta amino levulinic acid synthetase. Isolated reports have associated porphyria exacerbation with Rifacom EZ Kit (Rifampin) administration. The possibility of rapid emergence of resistant meningococci restricts the use of Rifacom EZ Kit (Rifampin) to short-term treatment of the asymptomatic carrier state. Rifacom EZ Kit (Rifampin) is not to be used for the treatment of meningococcal disease.

PRECAUTIONS

General

Rifacom EZ Kit should be used with caution in patients with a history of diabetes mellitus, as diabetes management may be more difficult.

Prescribing Rifacom EZ Kit (Rifampin) in the absence of a proven or strongly suspected bacterial infection or a prophylactic indication is unlikely to provide benefit to the patient and increases the risk of the development of drug-resistant bacteria.

For the treatment of tuberculosis, Rifacom EZ Kit (Rifampin) is usually administered on a daily basis. Doses of Rifacom EZ Kit (Rifampin) greater than 600 mg given once or twice weekly have resulted in a higher incidence of adverse reactions, including the "flu syndrome" (fever, chills and malaise), hematopoietic reactions (leukopenia, thrombocytopenia, or acute hemolytic anemia), cutaneous, gastrointestinal, and hepatic reactions, shortness of breath, shock, anaphylaxis, and renal failure. Recent studies indicate that regimens using twice-weekly doses of Rifacom EZ Kit (Rifampin) 600 mg plus isoniazid 15 mg/kg are much better tolerated.

Rifacom EZ Kit (Rifampin) is not recommended for intermittent therapy; the patient should be cautioned against intentional or accidental interruption of the daily dosage regimen since rare renal hypersensitivity reactions have been reported when therapy was resumed in such cases.

Rifacom EZ Kit (Rifampin) has enzyme induction properties that can enhance the metabolism of endogenous substrates including adrenal hormones, thyroid hormones, and vitamin D. Rifacom EZ Kit (Rifampin) and isoniazid have been reported to alter vitamin D metabolism. In some cases, reduced levels of circulating 25-hydroxy vitamin D and 1,25-dihydroxy vitamin D have been accompanied by reduced serum calcium and phosphate, and elevated parathyroid hormone.

Rifacom EZ Kit (Rifampin) for Injection

For intravenous infusion only. Must not be administered by intramuscular or subcutaneous route. Avoid extravasation during injection: local irritation and inflammation due to extravascular infiltration of the infusion have been observed. If these occur, the infusion should be discontinued and restarted at another site.

Information for Patients

Patients should be counseled that antibacterial drugs including Rifacom EZ Kit should only be used to treat bacterial infections. They do not treat viral infections (e.g., the common cold). When Rifacom EZ Kit (Rifampin) is prescribed to treat a bacterial infection, patients should be told that although it is common to feel better early in the course of therapy, the medication should be taken exactly as directed. Skipping doses or not completing the full course of therapy may (1) decrease the effectiveness of the immediate treatment and (2) increase the likelihood that bacteria will develop resistance and will not be treatable by Rifacom EZ Kit (Rifampin) or other antibacterial drugs in the future.

The patient should be told that Rifacom EZ Kit (Rifampin) may produce a reddish coloration of the urine, sweat, sputum, and tears, and the patient should be forewarned of this. Soft contact lenses may be permanently stained.

The patient should be advised that the reliability of oral or other systemic hormonal contraceptives may be affected; consideration should be given to using alternative contraceptive measures.

Patients should be instructed to notify their physicians promptly if they experience any of the following: fever, loss of appetite, malaise, nausea and vomiting, darkened urine, yellowish discoloration of the skin and eyes, and pain or swelling of the joints.

Compliance with the full course of therapy must be emphasized, and the importance of not missing any doses must be stressed.

Laboratory Tests

Adults treated for tuberculosis with Rifacom EZ Kit (Rifampin) should have baseline measurements of hepatic enzymes, bilirubin, serum creatinine, a complete blood count, and a platelet count (or estimate). Baseline tests are unnecessary in pediatric patients unless a complicating condition is known or clinically suspected.

Patients should be seen at least monthly during therapy and should be specifically questioned concerning symptoms associated with adverse reactions. All patients with abnormalities should have follow-up, including laboratory testing, if necessary. Routine laboratory monitoring for toxicity in people with normal baseline measurements is generally not necessary.

Drug Interactions

Healthy subjects who received Rifacom EZ Kit 600 mg once daily concomitantly with saquinavir 1000 mg/ritonavir 100 mg twice daily (ritonavir-boosted saquinavir) developed severe hepatocellular toxicity. Therefore, concomitant use of these medications is contraindicated. (See CONTRAINDICATIONS.)

Enzyme Induction

Rifacom EZ Kit (Rifampin) is known to induce certain cytochrome P-450 enzymes. Administration of Rifacom EZ Kit (Rifampin) with drugs that undergo biotransformation through these metabolic pathways may accelerate elimination of coadministered drugs. To maintain optimum therapeutic blood levels, dosages of drugs metabolized by these enzymes may require adjustment when starting or stopping concomitantly administered Rifacom EZ Kit (Rifampin).

Rifacom EZ Kit (Rifampin) has been reported to substantially decrease the plasma concentrations of the following antiviral drugs: atazanavir, darunavir, fosamprenavir, saquinavir, and tipranavir. These antiviral drugs must not be co-administered with Rifacom EZ Kit (Rifampin). (See CONTRAINDICATIONS .)

Rifacom EZ Kit (Rifampin) has been reported to accelerate the metabolism of the following drugs: anticonvulsants (e.g., phenytoin), digitoxin, antiarrhythmics (e.g., disopyramide, mexiletine, quinidine, tocainide), oral anticoagulants, antifungals (e.g., fluconazole, itraconazole, ketoconazole), barbiturates, beta-blockers, calcium channel blockers (e.g., diltiazem, nifedipine, verapamil), chloramphenicol, clarithromycin, corticosteroids, cyclosporine, cardiac glycoside preparations, clofibrate, oral or other systemic hormonal contraceptives, dapsone, diazepam, doxycycline, fluoroquinolones (e.g., ciprofloxacin), haloperidol, oral hypoglycemic agents (sulfonylureas), levothyroxine, methadone, narcotic analgesics, progestins, quinine, tacrolimus, theophylline tricyclic antidepressants (e.g., amitriptyline, nortriptyline) and zidovudine. It may be necessary to adjust the dosages of these drugs if they are given concurrently with Rifacom EZ Kit (Rifampin).

Patients using oral or other systemic hormonal contraceptives should be advised to change to nonhormonal methods of birth control during Rifacom EZ Kit (Rifampin) therapy.

Rifacom EZ Kit (Rifampin) has been observed to increase the requirements for anticoagulant drugs of the coumarin type. In patients receiving anticoagulants and Rifacom EZ Kit (Rifampin) concurrently, it is recommended that the prothrombin time be performed daily or as frequently as necessary to establish and maintain the required dose of anticoagulant.

Other Interactions

When the two drugs were taken concomitantly, decreased concentrations of atovaquone and increased concentrations of Rifacom EZ Kit were observed.

Concurrent use of ketoconazole and Rifacom EZ Kit (Rifampin) has resulted in decreased serum concentrations of both drugs. Concurrent use of Rifacom EZ Kit (Rifampin) and enalapril has resulted in decreased concentrations of enalaprilat, the active metabolite of enalapril. Dosage adjustments should be made if indicated by the patient's clinical condition.

Concomitant antacid administration may reduce the absorption of Rifacom EZ Kit (Rifampin). Daily doses of Rifacom EZ Kit (Rifampin) should be given at least 1 hour before the ingestion of antacids.

Probenecid and cotrimoxazole have been reported to increase the blood level of Rifacom EZ Kit (Rifampin).

When Rifacom EZ Kit (Rifampin) is given concomitantly with either halothane or isoniazid, the potential for hepatotoxicity is increased. The concomitant use of Rifacom EZ Kit (Rifampin) and halothane should be avoided. Patients receiving both Rifacom EZ Kit (Rifampin) and isoniazid should be monitored close for hepatotoxicity.

Plasma concentrations of sulfapyridine may be reduced following the concomitant administration of sulfasalazine and Rifacom EZ Kit (Rifampin). This finding may be the result of alteration in the colonic bacteria responsible for the reduction of sulfasalazine to sulfapyridine and mesalamine.

Drug/Laboratory Interactions

Cross-reactivity and false-positive urine screening tests for opiates have been reported in patients receiving Rifacom EZ Kit (Rifampin) when using the KIMS (Kinetic Interaction of Microparticles in Solution) method (e.g., Abuscreen OnLine opiates assay; Roche Diagnostic Systems). Confirmatory tests, such as gas chromatography/mass spectrometry, will distinguish Rifacom EZ Kit (Rifampin) from opiates.

Therapeutic levels of Rifacom EZ Kit (Rifampin) have been shown to inhibit standard microbiological assays for serum folate and vitamin B12. Thus, alternate assay methods should be considered. Transient abnormalities in liver function tests (e.g., elevation in serum bilirubin, alkaline phosphatase, and serum transaminases) and reduced biliary excretion of contrast media used for visualization of the gallbladder have also been observed. Therefore, these tests should be performed before the morning dose of Rifacom EZ Kit (Rifampin).

Carcinogenesis, Mutagenesis, Impairment of Fertility

A few cases of accelerated growth of lung carcinoma have been reported in man, but a causal relationship with the drug has not been established. Hepatomas were increased in female mice dosed for 60 weeks with rifampicin followed by an observation period of 46 weeks, at 20 to 120 mg/kg (equivalent to 0.1 to 0.5 times the maximum dosage used clinically, based on body surface area comparisons). There was no evidence of tumorigenicity in male C3Hf/DP mice or in similar studies in BALB/c mice, or in two year studies in Wistar rats.

There was no evidence of mutagenicity in both prokaryotic (Salmonella typhi, Escherichia coli) and eukaryotic (Saccharomyces cerevisiae) bacteria, Drosophila melanogaster, or ICR/Ha Swiss mice. An increase in chromatid breaks was noted when whole blood cell cultures were treated with Rifacom EZ Kit (Rifampin). Increased frequency of chromosomal aberrations was observed in vitro in lymphocytes obtained from patients treated with combinations of Rifacom EZ Kit (Rifampin), isoniazid, and pyrazinamide and combinations of streptomycin, Rifacom EZ Kit (Rifampin), isoniazid, and pyrazinamide.

Pregnancy

Teratogenic Effects

Category C

Rifacom EZ Kit has been shown to be teratogenic in rodents. Congenital malformations, primarily spina bifida were increased in the offspring of pregnant rats given Rifacom EZ Kit (Rifampin) during organogenesis at oral doses of 150 to 250 mg/kg/day (about 1 to 2 times the maximum recommended human dose based on body surface area comparisons). Cleft palate was increased in a dose-dependent fashion in fetuses of pregnant mice treated at oral doses of 50 to 200 mg/kg (about 0.2 to 0.8 times the maximum recommended human dose based on body surface area comparisons). Imperfect osteogenesis and embryotoxicity were also reported in pregnant rabbits given Rifacom EZ Kit (Rifampin) at oral doses up to 200 mg/kg/day (about 3 times the maximum recommended human dose based on body surface area comparisons). There are no adequate and well-controlled studies of Rifacom EZ Kit (Rifampin) in pregnant women. Rifacom EZ Kit (Rifampin) has been reported to cross the placental barrier and appear in cord blood. Rifacom EZ Kit (Rifampin) should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus.

Pregnancy

Non-Teratogenic Effects

When administered during the last few weeks of pregnancy, Rifacom EZ Kit can cause post-natal hemorrhages in the mother and infant for which treatment with vitamin K may be indicated.

Nursing Mothers

Because of the potential for tumorigenicity shown for Rifacom EZ Kit (Rifampin) in animal studies, a decision should be made whether to discontinue nursing or discontinue the drug, taking into account the importance of the drug to the mother.

Pediatric Use

See CLINICAL PHARMACOLOGY– Pediatrics ; see also DOSAGE AND ADMINISTRATION .

Geriatric Use

Clinical studies of Rifacom EZ Kit (Rifampin) did not include sufficient numbers of subjects aged 65 and over to determine whether they respond differently from younger subjects. Other reported clinical experience has not identified differences in responses between the elderly and younger patients. Caution should therefore be observed in using Rifacom EZ Kit (Rifampin) in elderly patients. (See WARNINGS ).

ADVERSE REACTIONS

Gastrointestinal

Heartburn, epigastric distress, anorexia, nausea, vomiting, jaundice, flatulence, cramps, and diarrhea have been noted in some patients. Although Clostridium difficile has been shown in vitro to be sensitive to Rifacom EZ Kit, pseudomembranous colitis has been reported with the use of Rifacom EZ Kit (Rifampin) (and other broad spectrum antibiotics). Therefore, it is important to consider this diagnosis in patients who develop diarrhea in association with antibiotic use.

Hepatic

Transient abnormalities in liver function tests (e.g., elevations in serum bilirubin,, alkaline phosphatase, serum transaminases) have been observed. Rarely, hepatitis or a shock-like syndrome with hepatic involvement and abnormal liver function tests has been reported.

Hematologic

Thrombocytopenia has occurred primarily with high dose intermittent therapy, but has also been noted after resumption of interrupted treatment. It rarely occurs during well supervised daily therapy. This effect is reversible if the drug is discontinued as soon as purpura occurs. Cerebral hemorrhage and fatalities have been reported when Rifacom EZ Kit administration has been continued or resumed after the appearance of purpura.

Rare reports of disseminated intravascular coagulation have been observed.

Leukopenia, hemolytic anemia, and decreased hemoglobin have been observed.

Agranulocytosis has been reported very rarely.

Central Nervous System

Headache, fever, drowsiness, fatigue, ataxia, dizziness, inability to concentrate, mental confusion, behavioral changes, muscular weakness pains in extremities, and generalized numbness have been observed.

Psychoses have been rarely reported.

Rare reports of disseminated intravascular coagulation have been observed.

Ocular

Visual disturbances have been observed.

Endocrine

Menstrual disturbances have been observed.

Rare reports of adrenal insufficiency in patients with compromised adrenal function have been observed.

Renal

Elevations in BUN and serum uric acid have been reported. Rarely, hemolysis, hemoglobinuria, hematuria, interstitial nephritis, acute tubular necrosis, renal insufficiency, and acute renal failure have been noted. These are generally considered to be hypersensitivity reactions. They usually occur during intermittent therapy or when treatment is resumed following intentional or accidental interruption of a daily dosage regimen, and are reversible when Rifacom EZ Kit is discontinued and appropriate therapy instituted.

Dermatologic

Cutaneous reactions are mild and self-limiting and do not appear to be hypersensitivity reactions. Typically, they consist of flushing and itching with or without a rash. More serious cutaneous reactions which may be due to hypersensitivity occur but are uncommon.

Hypersensitivity Reactions

Occasionally, pruritus, urticaria, rash, pemphigoid reaction, erythema multiforme including Stevens-Johnson Syndrome, toxic epidermal necrolysis, vasculitis, eosinophilia, sore mouth, sore tongue, and conjunctivitis have been observed.

Anaphylaxis has been reported rarely.

Miscellaneous

Edema of the face and extremities has been reported. Other reactions reported to have occurred with intermittent dosage regimens include "flu syndrome" (such as episodes of fever, chills, headache, dizziness, and bone pain), shortness of breath, wheezing, decrease in blood pressure and shock. The "flu syndrome" may also appear if Rifacom EZ Kit (Rifampin) is taken irregularly by the patient or if daily administration is resumed after a drug free interval.

OVERDOSAGE

Signs and Symptoms

Nausea, vomiting, abdominal pain, pruritus, headache, and increasing lethargy will probably occur within a short time after ingestion; unconsciousness may occur when there is severe hepatic disease. Transient increases in liver enzymes and/or bilirubin may occur. Brownish-red or orange discoloration of the skin, urine, sweat, saliva, tears, and feces will occur, and its intensity is proportional to the amount ingested.

Liver enlargement, possibly with tenderness, can develop within a few hours after severe overdosage; bilirubin levels may increase and jaundice may develop rapidly. Hepatic involvement may be more marked in patients with prior impairment of hepatic function. Other physical findings remain essentially normal. A direct effect upon the hematopoietic system, electrolyte levels, or acid-base balance is unlikely.

Facial or periorbital edema has also been reported in pediatric patients. Hypotension, sinus tachycardia, ventricular arrhythmias, seizures and cardiac arrest were reported in some fatal cases.

Acute Toxicity

The minimum acute lethal or toxic dose is not well established. However, nonfatal acute overdoses in adults have been reported with doses ranging from 9 to 12 gm Rifacom EZ Kit. Fatal acute overdoses in adults have been reported with doses ranging from 14 to 60 gm. Alcohol or a history of alcohol abuse was involved in some of the fatal and nonfatal reports. Nonfatal overdoses in pediatric patients ages 1 to 4 years old of 100 mg/kg for one to two doses has been reported.

Treatment

Intensive support measures should be instituted and individual symptoms treated as they arise. The airway should be secured and adequate respiratory exchange established. Since nausea and vomiting are likely to be present, gastric lavage within the first 2 to 3 hours after ingestion is probably preferable to induction of emesis. Following evacuation of the gastric contents, the instillation of activated charcoal slurry into the stomach may help absorb any remaining drug from the gastrointestinal tract. Antiemetic medication may be required to control severe nausea and vomiting.

Active diuresis (with measured intake and output) will help promote excretion of the drug.

For severe cases, extracorporeal hemodialysis may be required. If this is not available, peritoneal dialysis can be used along with forced diuresis.

DOSAGE AND ADMINISTRATION

Rifacom EZ Kit can be administered by IV infusion (see INDICATIONS AND USAGE ).

See CLINICAL PHARMACOLOGY for dosing information in patients with renal failure.

Tuberculosis

Adults: 10 mg/kg, in a single daily administration, not to exceed 600 mg/day, IV

Pediatric Patients: 10–20 mg/kg, not to exceed 600 mg/day, IV

Rifacom EZ Kit (Rifampin) is indicated in the treatment of all forms of tuberculosis. A three-drug regimen consisting of Rifacom EZ Kit (Rifampin), isoniazid, and pyrazinamide (e.g., RIFATER® manufactured by Sanofi Aventis) is recommended in the initial phase of short-course therapy which is usually continued for 2 months. The Advisory Council for the Elimination of Tuberculosis, the American Thoracic Society, and the Centers for Disease Control and Prevention recommend that either streptomycin or ethambutol be added as a fourth drug in a regimen containing isoniazid (INH), Rifacom EZ Kit (Rifampin) and pyrazinamide for initial treatment of tuberculosis unless the likelihood of INH resistance is very low. The need for a fourth drug should be reassessed when the results of susceptibility testing are known. If community rates of INH resistance are currently less than 4%, an initial treatment regimen with less than four drugs may be considered.

Following the initial phase, treatment should be continued with Rifacom EZ Kit (Rifampin) and isoniazid (e.g., RIFAMATE® manufactured by Sanofi Aventis) for at least 4 months. Treatment should be continued for longer if the patient is still sputum or culture positive, if resistant organisms are present, or if the patient is HIV positive.

Preparation of Solution for IV Infusion

Reconstitute the lyophilized powder by transferring 10 mL of sterile water for injection to a vial containing 600 mg of Rifacom EZ Kit for injection. Swirl vial gently to completely dissolve the antibiotic. The reconstituted solution contains 60 mg Rifacom EZ Kit (Rifampin) per mL and is stable at room temperature for 24 hours. Prior to administration, withdraw from the reconstituted solution a volume equivalent to the amount of Rifacom EZ Kit (Rifampin) calculated to be administered and add to 500 mL of infusion medium. Mix well and infuse at a rate allowing for complete infusion within 3 hours. Alternatively, the amount of Rifacom EZ Kit (Rifampin) calculated to be administered may be added to 100 mL of infusion medium and infused in 30 minutes.

Dilutions in dextrose 5% for injection (D5W) are stable at room temperature for up to 4 hours and should be prepared and used within this time. Precipitation of Rifacom EZ Kit (Rifampin) from the infusion solution may occur beyond this time. Dilutions in normal saline are stable at room temperature for up to 24 hours and should be prepared and used within this time. Other infusion solutions are not recommended.

Incompatibilities

Physical incompatibility (precipitate) was observed with undiluted (5 mg/mL) and diluted (1 mg/mL in normal saline) diltiazem hydrochloride and Rifacom EZ Kit (Rifampin) (6 mg/mL in normal saline) during simulated Y-site administration.

Meningococcal Carriers

Adults: For adults, it is recommended that 600 mg Rifacom EZ Kit (Rifampin) be administered twice daily for two days.

Pediatric Patients: Pediatric patients 1 month of age or older: 10 mg/kg (not to exceed 600 mg per dose) every 12 hours for two days.

Pediatric patients under 1 month of age: 5 mg/kg every 12 hours for two days.

HOW SUPPLIED

Rifacom EZ Kit for injection, USP is available in glass vials containing 600 mg Rifacom EZ Kit (Rifampin) (NDC 0069-0112-01).

Storage

Store at 25°C (77°F); excursions permitted to 15–30°C (59–86°F). Avoid excessive heat (temperatures above 40°C or 104°F). Protect from light.

References

  • Clinical Laboratory Standards Institute, Susceptibility Testing of Mycobacteria, Nocardiae, and Other Aerobic Actinomycetes; Approved Standard CLSI Document M24-A, Vol. 23, No. 18, CLSI, Villanova, PA, 2003.
  • Clinical Laboratory Standards Institute. Methods for Dilution Antimicrobial Susceptibility Tests for Bacteria that Grow Aerobically -- Eighth Edition. Approved Standard CLSI Document M7-A8, Vol. 29, No. 2, CLSI, Villanova, PA, January 2009.
  • Clinical Laboratory Standards Institute. Performance Standards for Antimicrobial Disk Susceptibility Tests -- Tenth Edition. Approved Standard CLSI Document M2-A10, Vol. 29, No. 41,, CLSI, Villanova, PA, January 2009.
  • Clinical Laboratory Standards Institute. Performance Standards for Antimicrobial Susceptibility Testing; Twentieth Informational Supplement, CLSI Document M100-S20, Vol. 30, No. 1, CLSI, Villanova, PA, January 2010.

Logo

LAB-0463-1.0

March 2013

NDC 0069-0112-01

1 Vial

Rifacom EZ Kit (Rifampin) for

Injection, USP

600 mg/vial

Sterile

For IV Infusion Only

Pfizer Injectables

Rx only

Rifacom EZ Kit pharmaceutical active ingredients containing related brand and generic drugs:

Active ingredient is the part of the drug or medicine which is biologically active. This portion of the drug is responsible for the main action of the drug which is intended to cure or reduce the symptom or disease. The other portions of the drug which are inactive are called excipients; there role is to act as vehicle or binder. In contrast to active ingredient, the inactive ingredient's role is not significant in the cure or treatment of the disease. There can be one or more active ingredients in a drug.


Rifacom EZ Kit available forms, composition, doses:

Form of the medicine is the form in which the medicine is marketed in the market, for example, a medicine X can be in the form of capsule or the form of chewable tablet or the form of tablet. Sometimes same medicine can be available as injection form. Each medicine cannot be in all forms but can be marketed in 1, 2, or 3 forms which the pharmaceutical company decided based on various background research results.
Composition is the list of ingredients which combinedly form a medicine. Both active ingredients and inactive ingredients form the composition. The active ingredient gives the desired therapeutic effect whereas the inactive ingredient helps in making the medicine stable.
Doses are various strengths of the medicine like 10mg, 20mg, 30mg and so on. Each medicine comes in various doses which is decided by the manufacturer, that is, pharmaceutical company. The dose is decided on the severity of the symptom or disease.


Rifacom EZ Kit destination | category:

Destination is defined as the organism to which the drug or medicine is targeted. For most of the drugs what we discuss, human is the drug destination.
Drug category can be defined as major classification of the drug. For example, an antihistaminic or an antipyretic or anti anginal or pain killer, anti-inflammatory or so.


Rifacom EZ Kit Anatomical Therapeutic Chemical codes:

A medicine is classified depending on the organ or system it acts [Anatomical], based on what result it gives on what disease, symptom [Therapeutical], based on chemical composition [Chemical]. It is called as ATC code. The code is based on Active ingredients of the medicine. A medicine can have different codes as sometimes it acts on different organs for different indications. Same way, different brands with same active ingredients and same indications can have same ATC code.


Rifacom EZ Kit pharmaceutical companies:

Pharmaceutical companies are drug manufacturing companies that help in complete development of the drug from the background research to formation, clinical trials, release of the drug into the market and marketing of the drug.
Researchers are the persons who are responsible for the scientific research and is responsible for all the background clinical trials that resulted in the development of the drug.


advertisement

References

  1. Dailymed."PYRAZINAMIDE TABLET [A-S MEDICATION SOLUTIONS]". https://dailymed.nlm.nih.gov/dailym... (accessed August 28, 2018).
  2. Dailymed."RIFAMPIN INJECTION, POWDER, LYOPHILIZED, FOR SOLUTION [PFIZER LABORATORIES DIV PFIZER INC]". https://dailymed.nlm.nih.gov/dailym... (accessed August 28, 2018).
  3. Dailymed."ISONIAZID TABLET [BRYANT RANCH PREPACK]". https://dailymed.nlm.nih.gov/dailym... (accessed August 28, 2018).

Frequently asked Questions

Can i drive or operate heavy machine after consuming Rifacom EZ Kit?

Depending on the reaction of the Rifacom EZ Kit after taken, if you are feeling dizziness, drowsiness or any weakness as a reaction on your body, Then consider Rifacom EZ Kit 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 Rifacom EZ Kit 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.

advertisement

Review

sdrugs.com conducted a study on Rifacom EZ Kit, and the result of the survey is set out below. It is noteworthy that the product of the survey is based on the perception and impressions of the visitors of the website as well as the views of Rifacom EZ Kit consumers. We, as a result of this, advice that you do not base your therapeutic or medical decisions on this result, but rather consult your certified medical experts for their recommendations.

Visitor reports

Visitor reported useful

No survey data has been collected yet

Visitor reported side effects

No survey data has been collected yet

Visitor reported price estimates

No survey data has been collected yet

Visitor reported frequency of use

No survey data has been collected yet

Visitor reported doses

No survey data has been collected yet

Visitor reported time for results

No survey data has been collected yet

Visitor reported administration

No survey data has been collected yet

Visitor reported age

No survey data has been collected yet

Visitor reviews


There are no reviews yet. Be the first to write one!


Your name: 
Email: 
Spam protection:  < Type 17 here

The information was verified by Dr. Rachana Salvi, MD Pharmacology

© 2002 - 2022 "sdrugs.com". All Rights Reserved