The Sound of Evolution
Mexiletine
Mechanism of action:
Mexiletine is a class IB sodium-channel blocker and is structurally similar to lidocaine. Mexiletine preferentially binds to sodium channels in cardiac muscle cells when they are in the activated or inactivated state, with little preference for the resting state. It reduces depolarization, shortens action potential duration, and shortens the effective refractory period.
Reference(s):
1. Valdivia CR et al. (2002). A novel SCN5A arrhythmia mutation, M1766L, with expression defect rescued by mexiletine. Cardiovasc Res.
2. Chinushi M et al. (2003). Ventricular tachyarrhythmias in a canine model of LQT3: arrhythmogenic effects of sympathetic activity and therapeutic effects of mexiletine. Circ J.
3. Fabritz L et al. (2003). Effect of pacing and mexiletine on dispersion of repolarisation and arrhythmias in DeltaKPQ SCN5A (long QT3) mice. Cardiovasc Res.