The effect of tricyclic antidepressant drugs on the heart

Abstract

The effects on the heart rate and ECG of anaesthetised guinea-pigs of amitriptyline, doxepin, imipramine and nortriptyline infused at 1.0 mg/kg/min until death were observed. In addition an in vitro study on guinea-pig atria was performed on the chronotropic and inotropic effects of these drugs and of desmethylimipramine and protriptyline at a concentration of 10-5 M. The effect of sodium bicarbonate (3 mEq/kg i.v.) and propranolol (0.01-0.2 mg/kg i.v.) on amitriptyline and doxepin induced ECG changes was also assessed. A difference in the cardiac effects of the in vivo and in vitro model was observed. Guinea-pigs infused with doxepin survived significantly longer than those infused with ami..