The Sound of Evolution
Mexiletine
美西律
Mechanism of action:
Mexiletine 是一種 class IB 鈉離子通道阻斷劑（class IB sodium-channel blocker），結構上與利多卡因（lidocaine）類似。Mexiletine 優先結合於心肌細胞上處於活化和不活化狀態的鈉離子通道（sodium channel）（不偏好休息狀態，resting state），減弱去極化（depolarization）、縮短動作電位持續時間（action potential duration）、縮短有效不反應期（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.