THE CARDIOVASCULAR AND EXTRAVASCULAR SMOOTH MUSCLE ACTIONS OF CHLORPHENTERMINE HYDROCHLORIDE (p-CHLORO-,-DIMETHYLPHENETHYLAMINE)—A NEW ANOREXIGENIC AGENT

¹ Department of Pharmacology, Warner-Lambert Research Institute, Morris Plains, New Jersey

The results of these studies have demonstrated that chlorphentermine has a cardiovascular profile similar to that of diethylpropion and d-amphetamine. The 3 compounds have positive chronotropic and inotropic effects upon the heart in situ and produce a pressor response which is prolonged in duration. When administered directly into the coronary artery, each caused a rapid but brief increase in coronary blood flow. Intraarterial injections into the femoral artery evoked a transient vasoconstriction. Although the compounds were qualitatively similar in their cardiovascular activity their relative potencies were dependent upon the route of administration. Diethylpropion and d-amphetamine differed from chlorphentermine in that they augmented the pressor response of norepinephrine. In addition, they produced tachyphylaxis.

Chlorphentermine and diethylpropion consistently depressed nonvascular smooth muscle both in vitro and in vivo. This action was transient and required large doses to produce the above effect. d-Amphetamine was similar in action to the other two agents in being a depressant to smooth muscle in vivo; it differed from them in being either inactive or having a stimulant action on in vitro preparations.