Hypotensive action of chlorpromazine.

Abstract

It is generally recognized that chlorpromazine (10-[y-diethylaminopropyl]-2-chlorophenothiazine hydro-chloride) may, in some cases, cause a moderate reduction of blood pressure. Usually this reduction is not of sufficient magnitude to cause clinical symptoms, but we have previously noted syncope with orthostatic hypotension following the administration of the drug. The incidence of such a reaction is small. Of more than 300 patients who were given chlorpromazine, a reduction in blood pressure so marked that they required intensive therapy developed in only 7. The present report concerns these seven patients, all of whom were hospitalized. REPORT OF CASES Case 1.—A 58-year-old woman, a known chronic alcoholic, was admitted to the hospital because of tremors and hallucinations. Physical examination disclosed blood pressure of 120/70 mm. Hg, rectal temperature 99 F, pulse rate 90, respiratory rate 20, and no evidence of other disease. The patient was given 100 mg. of chlorpromazine intramuscularly; three hours later she