Hypotension due to chlorpromazine. Relation to cigarette smoking, blood pressure, and dosage.

The frequency of hypotension attributed to orally administered chlorpromazine hydrochloride was compared among 187 nonsmokers, 223 "light" smokers, 87 "intermediate" smokers, and 18 "heavy" smokers. Hypotension attributed to the drug occurred in10%, 8%, 5% and 0%, respectively. Other factors found to be independently related to hypotension were high diastolic blood pressure on admission and high dosage of chlorpromazine. The results suggest that smoking status, dosage, and blood pressure must be evaluated in order to estimate the likelihood that a patient may become hypotensive after receiving chlorpromazine.