Experimental cerebral vasospasm: resolution by chlorpromazine.

Vasospasm of the cat basilar artery was produced by electrical, mechanical, or chemical stimuli or by subarachnoid hemorrhage. The vasospasm induced by these stimuli was relieved by the topical application of chlorpromazine to the vascular wall. Chlorpromazine appears to be a nonspecific vasoparalytic agent. Unlike previously used substances, it is effective in resolving vasospasm caused by mechanical as well as chemical irritation.