Loxicard is an antiarrhythmic agent of class IB, local anesthetic, a derivative of acetanilide. This medication has membrane stabilizing activity. Loxicard causes a blockade of sodium channels of excitable membranes of neurons and the membrane of cardiomyocytes.
This drug reduces the duration of the action potential and effective refractory period in Purkinje fibers, inhibits their automaticity. In this case, Loxicard inhibits electrical activity in depolarized, arrhythmogenic sites, but minimally affects the electrical activity of normal tissues. When used in the medium therapeutic doses virtually no effect on myocardial contractility and slows AV-conduction. When applied as an antiarrhythmic agent in IV injection it begin to act in 45-90 seconds, the duration of action is 10-20 minutes; for IM administration the onset of action is in 5-15 minutes, the duration - 60-90 minutes.
Loxicard causes all kinds of local anesthesia: a terminal, infiltration and wires.
After IM administration absorption of Loxicard is almost complete. The distribution is rapid, Vd is about 1 L/kg (in patients with heart failure it is below). The protein binding depends on the concentration of the active substance in the plasma and is 60-80%. Loxicard metabolized mainly in the liver with the formation of active metabolites, that may contribute to the manifestation of the therapeutic and toxic effects, especially after the infusion for 24 hours or more.
T1/2 tends to be two phases with the phase distribution of 9.7 min. In general T1/2 depends on the dose is 1-2 hours and can grow up to 3 hours or more during prolonged intravenous infusion (over 24 h). Loxicard excreted by the kidneys as metabolites, 10% unchanged.
Why is Loxicard prescribed?
In cardiological practice: treatment and prevention of ventricular arrhythmias (extrasystoles, tachycardia, atrial flutter, atrial fibrillation), including in acute myocardial infarction, implantation of artificial pacemaker in the glycoside intoxication, narcosis.
Anaesthesia: terminal, infiltration, conduction, spinal (epidural) anesthesia in surgery, obstetrics and gynecology, urology, ophthalmology, dentistry, otolaryngology, blockade of peripheral nerves and ganglion.
Dosage and administration
As an anti-arrhythmic medicine for adult with the introduction of a loading dose by IV - 1-2 mg / kg over 3-4 minutes; the average single dose is 80 mg. Then immediately transferred to drip infusion at a rate of 20-55 mg / kg / min. Drip infusion can be carried out within 24-36 hours. If necessary, against the background of drop infusions can repeat IV jet injection of Loxicard 40 mg after 10 minutes after the first loading dose.
IM is introduced to 2-4 mg / kg, if necessary, repeated administration is possible through 60-90 minutes.
For children with IV injection loading dose - 1 mg / kg, if necessary, it may be repeated administration in 5 min.
For continuous intravenous infusion (usually following the introduction of a loading dose) - 20-30 mg / kg / min.
For use in surgical and obstetric practice, dentistry, ENT practice, dosing regimen set individually, depending on the evidence, the clinical situation and used the dosage form.
Maximum dose: for adults for IV injections the loading dose is 100 mg, in a subsequent drop infusion it is 2 mg / min; when IM administration - 300 mg (about 4.5 mg / kg) for 1 h.
For children in case of reintroduction the loading dose every 5 minutes, the total dose is 3 mg / kg; by continuous intravenous infusion (usually following the introduction of a loading dose) - 50 mg / kg / min.
Loxicard side effects, adverse reactions
CNS and peripheral nervous system: dizziness, headache, weakness, motor restlessness, nystagmus, loss of consciousness, drowsiness, visual and auditory disturbances, tremor, trismus, seizures (risk of their development against the backdrop of increasing hypercapnia and acidosis), a syndrome of "cauda equina" (paralysis of the legs, paresthesia), paralysis of respiratory muscles, respiratory arrest, a block of motor and sensitive, respiratory paralysis (usually develops in the subarachnoid anesthesia), numb tongue (when used in dentistry).
Cardiovascular system: increased or decreased blood pressure, tachycardia if used with a vasoconstrictor, peripheral vasodilatation, collapse, chest pain.
Digestive system: nausea, vomiting, involuntary defecation.
Allergic reactions: skin rash, hives (on skin and mucous membranes), itching, angioedema, anaphylactic shock.
Local reactions: during spinal anesthesia - a pain in the back, with an epidural anesthesia - a random hit in the subarachnoid space, when applied topically in urology - urethritis.
Other: incontinent, methemoglobinemia, persistent anesthesia, decreased libido and / or potency, respiratory depression, until the stop, hypothermia; during anesthesia in dentistry: numbness and paresthesia of the lips and tongue, the lengthening of anesthesia.
Severe bleeding, shock, hypotension, infection of the proposed injection site, marked bradycardia, cardiogenic shock, severe forms of chronic heart failure, SSS in elderly patients, AV-block II and III degree (except in cases when the probe was introduced to stimulate the ventricles), severe liver function abnormalities.
For subarachnoid anesthesia - complete heart block, bleeding, hypotension, shock, infection of the venue lumbar puncture, septicemia.
Increased sensitivity to Loxicard and other amide type local anesthetics.
Using during pregnancy and breastfeeding
During pregnancy and lactation be used only for health reasons. Loxicard is excreted in breast milk.
In obstetric practice used with caution in paracervical for violations of fetal development, placental insufficiency, prematurity, postmaturity, gestosis.
Category effects on the fetus by FDA - B.
Use with caution in liver disease and kidney failure, hypovolemia, severe heart failure, in violation of the contractility of genetic susceptibility to malignant hyperthermia. In children, debilitated patients, elderly patients are required in dosage adjustment in accordance with the age and physical status. When injected into vascularized tissue it is recommended an aspiration test.
Loxicard drug interactions
Beta-blockers increase the risk of bradycardia and hypotension. Norepinephrine and beta-blockers by reducing hepatic blood flow decrease (increased toxicity), isadrine and glucagon - increase the clearance of lidocaine. Cimetidine increases the plasma concentration of Loxicard (displaces from its association with proteins and slows inactivation in the liver). Barbiturates causing induction of microsomal enzymes stimulate the degradation of Loxicard and reduce its activity. Anticonvulsants (hydantoin derivatives) accelerate the biotransformation in the liver (decreased concentration in the blood), for IV injections it may increases cardiodepressive action of lidocaine. Antiarrhythmics (amiodarone, verapamil, quinidine, aymalin) potentiate cardiac depression. Combination with novocainamide may cause CNS excitement and hallucinations. Loxicard strengthens the inhibitory effect of anesthesia (hexobarbital, thiopental sodium), hypnotics and sedatives on the respiratory center, weakens the cardiac effects of digitoxin, enhances muscle relaxation caused by drugs curare like (possible paralysis of respiratory muscles). MAO inhibitors prolong local anesthesia.
Loxicard in case of emergency / overdose
Symptoms: psychomotor agitation, dizziness, weakness, decreased blood pressure, tremors, tonic-clonic convulsions, coma, collapse, possible AV blockade, CNS depression, respiratory arrest.
Treatment: discontinuation, pulmonary ventilation, oxygen therapy, anticonvulsants, vasoconstrictors (norepinephrine, mezaton), when bradycardia - anticholinergics (atropine). It is possible to carry out intubation, mechanical ventilation, resuscitation. Dialysis is ineffective.