Mexiletine hydrochloride

Описание

Mexiletine is a voltage-gated sodium channel blocker and class Ib antiarrhythmic agent that preferentially binds to open/inactive channels. It inhibits aconitine-induced dysrhythmias in mice with ED₅₀ values of 57 and 107 mg/kg for intraperitoneal and oral administration, respectively. Mexiletine decreases or inhibits conduction across the Purkinje fiber-muscle junction, shortens action potential duration, and decreases the refractory period when used at concentrations less than 5 μg/ml in isolated canine Purkinje fiber and ventricular muscle preparations.

Химические свойства

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Использование

Mexiletine hydrochloride has been used as a sodium channel blocker:

• expressed in chinese hamster ovary cells
• in human embryonic kidney (HEK) cells for whole cell patch-clamp studies
• electrophysiology studies in HEK cells expressing Nav1.7 protein

Определение

ChEBI: A hydrochloride composed of equimolar amounts of mexiletine and hydrogen chloride.

Общее описание

Mexiletine hydrochloride,1-methyl-2-(2,6-xylyloxy)ethylamine hydrochloride (Mexitil)(pKa 8.4), is a class IB antiarrhythmic agent that is effectivewhen given either intravenously or orally. It resembles lidocainein possessing a xylyl moiety but otherwise is differentchemically. Mexiletine hydrochloride is an ether and is notsubject to the hydrolysis common to the amides lidocaineand tocainide. Its mean half-life on oral administration isapproximately 10 hours.
Although not subject to hydrolysis, mexiletine hydrochlorideis metabolized by oxidative and reductiveprocesses in the liver. Its metabolites, p-hydroxymexiletineand hydroxymethylmexiletine, are not pharmacologicallyactive as antiarrhythmic agents.

Биологическая активность

Use-dependent sodium channel blocker (IC 50 values are 75.3 and 23.6 μ M for tonic and use-dependent block respectively). Class Ib antiarrhythmic, neuroprotective and antimyotonic agent.

Клиническое использование

Mexiletine hydrochloride, like class I antiarrhythmicagents, blocks the fast Na channel in cardiac cells. It isespecially effective on the Purkinje fibers in the heart. Thedrug increases the threshold of excitability of myocardialcells by reducing the rate of rise and amplitude of the actionpotential and decreases automaticity.
Mexiletine hydrochloride is used for long-term oral prophylaxisof ventricular tachycardia. The drug is given in200- to 400-mg doses every 8 hours.