Mexiletine hydrochloride 是钠离子通道 (voltage-gated Sodium Channel) 阻断剂，属于 Class IB 类抗心律失常化合物。

Mexiletine Hydrochloride is the hydrochloride salt form of mexiletine, a local anesthetic and antiarrhythmic (Class IB) agent structurally related to lidocaine. Mexiletine exerts its antiarrhythmic effect by inhibiting the inward sodium current in cardiac cells, thereby reducing the rate of rising of the cardiac action potential (phase 0) and decreases automaticity in the Purkinje fibers. This slows nerve impulses in the heart and stabilizes the heartbeat. Mexiletine's anesthetic activity is due to its ability to block sodium influx in peripheral nerves, thereby reducing the rate and intensity of pain impulses reaching the central nervous system.

Mexiletine口服的生物利用度为90％.Mexiletine起效迅速且具有抵消动力学,表明其仅在心率较快时有较大作用,当心率较慢时则几乎不起作用.

Mexiletine对心脏浦肯野纤维有效不应期（ERP）的缩短比对动作电位持续时间（APD）的少,使ERP/APD比率变高。Mexiletine对房室传导速度,静息膜电位,窦房结自律性,收缩期动脉压,左心室功能,QRS或QT间隔均无明显影响。Mexiletine通过抑制钠通道抑制钠离子内流（需要脉冲启动和传导）,进而使动作电位升高速率降低。

5370-01-4

C11H18ClNO

215.72

Mexiletine HCl;KOE-1173 (hydrochloride);KO1173;盐酸美西律

DMSO:21.6 mg/mL (100 mM)
H2O:21.6 mg/mL (100 mM)
Powder: -20°C for 3 years
In solvent: -80°C for 2 years