Carsatrin free base is purinylpiperazine derivative. as cardiotonic and antiarrhythmic. Carsatrin free base acts as positive inotropic agent that increases twitch tension and prolongs the action potential (AP) duration of ventricular muscle without affecting the Na+, K+-ATPase, adenylyl cyclase, phosphodiesterase isozymes, or cardiac myofilaments. Carsatrin free base’s positive inotropic effect can be prevented by tetrodotoxin but not by the adrenergic antagonists timolol, yohimbine, or prazosin