Cardiovascular effects of some phenothiazine derivatives following intracoronary injection in dogs.

The cardiovascular effects of phenothiazine derivatives in general and chlorpromazine in particular are quite complex (4·6, 1], 13, 14, 17) because such drugs produce direct effects on the heart and blood vessels, and also indirect ones through actions on C.N.S. and autonomic reflexes. Hypotension most commonly seen, is pnmirily due to inhibition of cetrally mediated pressor reflexes, but peripheral adrenergic blockade may also play a role (7). Reflex tachycardia is commonly seen following administration of chlorpromazine because of lowered peripheral resistance and resulting hypotension.