Mexiletine

Overview
Mexiletine (INN, sold under the trade name Mexitil®) belongs to the Class IB anti-arrhythmic group of medicines. It is used to treat arrhythmias within the heart - or seriously irregular heartbeats. It slows nerve impulses in the heart and makes the heart tissue less sensitive. Dizziness, heartburn, nausea, nervousness, trembling, unsteadiness are common side effects. It is available in injection and capsule form.

Class IB antiarrhythmics decrease action potential duration by shortening the repolarization phase. This is achieved by blocking sodium channels.

Mexiletine may also be of use in patients experiencing refractory pain. (Sweetman, 2002) and is also effective for treating muscle stiffness resulting from myotonia congenita (Thomsen disease)