Mexaritm (mexiletine hydrochloride) capsules 0.2 g. №20

Description

Mexaritm composition
active substance: mexiletine hydrochloride;
1 capsule contains 200 mg of mexiletine hydrochloride in terms of 100% dry matter;
excipients: lactose monohydrate, calcium stearate.

Dosage form
Capsules.

Pharmacological properties
Meksiletina hydrochloride belongs to class IV antiarrhythmic drugs. It inhibits the fast transmembrane current of sodium ions, has a membrane stabilizing and local anesthetic effect. The drug Mexaritm reduces the rate of depolarization and automatism of pacemakers, the rate of conduction of excitation in the fibers of His-Purkinje, slightly decreases the effective refractory period and, to a greater extent, the duration of the action potential (AP), increases the ratio of the effective refractory period to the duration of AP. Mexiletin has little effect on hemodynamic parameters.

Indications
Treatment of documented ventricular arrhythmias such as persistent ventricular tachycardia, extrasystoles.
Given the arrhythmogenic effect of the drug and the lack of evidence that class I antiarrhythmic drugs improve the survival rate of patients with asymptomatic ventricular arrhythmias, the drug is prescribed only for arrhythmias that are considered life-threatening by the doctor.

Contraindications
Hypersensitivity to mexiletine, to other constituents of the drug, to local anesthetics (for example, lidocaine);

• cardiogenic shock;
• severe bradycardia;
• severe arterial hypotension;
• AV block II and III degree in the absence of an artificial pacemaker;
• the first 3 months after myocardial infarction, with a left ventricular ejection fraction of less than 35%.

Children
There are no data on the safety and effectiveness of the drug for the treatment of children.

Application during pregnancy or lactation
The use of the drug during pregnancy is contraindicated, except in special cases (life-threatening ventricular rhythm disturbances).
Mexiletin is excreted in breast milk in concentrations that can affect the child, therefore, if it is necessary to take the drug by women who are breastfeeding, feeding should be discontinued for the period of treatment.

Method of administration and dosage
Treatment with mexiletine, like other antiarrhythmic drugs used to treat life-threatening arrhythmias, should be started in a hospital with mandatory clinical, laboratory and ECG monitoring of the patient’s condition and the antiarrhythmic effect of treatment, especially in patients with sinus node dysfunction, conduction disturbances, bradycardia, arterial hypotension, with severe cardiac, renal and hepatic failure.
The dosage of Mexaritm should be individualized and depends on the therapeutic effect and the tolerability of the drug.
The capsule should be swallowed without chewing, during or after a meal and with plenty of liquid.
If rapid control of ventricular arrhythmia is required, the saturation dose of Mexaritm is 400 mg (2 capsules). In the future (2 hours after taking the saturation dose), they switch to a maintenance dose of 200 mg (1 capsule) every 6-8 hours. In some cases, the saturation dose (for example, in acute myocardial infarction) may be 600 mg.
The onset of the therapeutic effect, as a rule, is observed after 30 minutes, reaching a maximum after 2 hours. The usual daily dose is 600-800 mg, which is divided into 3-4 doses.
Mexaritm treatment can be started with a dose of 200 mg every 8 hours. If the antiarrhythmic effect is not achieved, the dose should be increased to 400 mg every 8 hours. A satisfactory result is usually achieved with a 200 mg 3 times daily regimen.
The risk and severity of side effects increases with the daily dose, so it should not exceed 1200 mg.
The duration of treatment depends on the severity and course of the disease. Discontinuation of treatment after stabilization of the rhythm should be gradual – within 1-2 weeks.
there is no treatment for children.

Overdose
Symptoms: drowsiness, confusion, nausea, vomiting, ataxia, convulsions. Symptoms from the organs of vision (diplopia, nystagmus), paresthesia were also observed. However, the more typical manifestations of overdose are severe arterial hypotension, sinus bradycardia, AV blockade, asystole, ventricular tachyarrhythmia, including fibrillation, cardiovascular collapse, coma.
Treatment: symptomatic. If necessary, gastric lavage is performed, the patient must be transferred to intensive care for cardiopulmonary support. In the case of severe bradycardia and arterial hypotension, atropine is given intravenously, and diazepam can be used for convulsions.

Side effects:

• Digestive tract: nausea, vomiting, heartburn, hiccups, abdominal pain, diarrhea or constipation, changes in salivation / dry mouth / changes in the oral mucosa, changes in taste; isolated cases of dysphagia, esophageal, peptic ulcers, rarely – gastrointestinal bleeding.
• Nervous system: dizziness, tremors, impaired coordination, irritability, sleep disturbances (including drowsiness), weakness, fatigue, headache, dysarthria, ringing in the ears, nystagmus, impaired accommodation, impaired concentration, paresthesia, convulsions, confusion, loss of consciousness, mental disorders, hallucinations, depression, possible short-term memory loss.
• Cardiovascular system: palpitation, pain in the region of the heart, syncope, arterial hypotension / hypertension, hot flashes, bradycardia, manifestations of arrhythmogenic properties of the drug (atrial fibrillation / flutter, ventricular extrasystole, atrioventricular dissociation, atrioventricular block or impaired conduction) existing arrhythmia), the development of congestive heart failure, cardiogenic shock is possible.
• Blood system and lymphatic system: thrombocytopenia, leukopenia (including neutropenia and agranulocytosis).
• Respiratory system: dyspnea, there have been reports of isolated cases of interstitial pneumonitis, pulmonary infiltrates, pulmonary fibrosis.
• Hepatobiliary system: increased activity of liver enzymes, especially in the first weeks of taking the drug. Reported isolated cases of liver dysfunction, incl. jaundice, severe hepatitis / acute liver necrosis.
• Skin and subcutaneous tissue: rashes, edema, dry skin, alopecia, diaphoresis, isolated cases of erythroderma, exfoliative dermatitis and Stevens-Johnson syndrome.
• Immune system: hypersensitivity, lupus-like syndrome, positive titers of antinuclear factors.
• Genitourinary system: impotence / decreased libido, impaired urination (including urinary retention), renal failure.
• Other: visual impairment, incl. diplopia, laryngitis and pharyngitis (dryness of the mucous membranes), arthralgia, fever.

Shelf life
3 years.
Do not use the drug after the expiration date printed on the package.

Storage conditions
In its original packaging at a temperature not exceeding 25 ° C. Keep out of the reach of children.