Influence of Dimethylaminoethylbenzhydryl Ether Hydrochloride Upon Histamine Flare Reactions

Abstract

In 10 subjects without known disturbance of the autonomic nervous system di-methylaminoethylbenzhydryl ether hydrochloride (benadryl) caused a reduction in the cutaneous responses to histamine when given by mduth in divided doses totally as little as 150 mg. daily for periods of 0.5 wks. or more. Maximum effects with the complete disappearance of the triple skin reaction were obtained after the admin. of 300 mg. daily for 2 wks. No tolerance to the drug was observed even after 18 wks. of ingestion. After discontinuance, however, for a brief period, the responses to histamine were increased, reaching as much as 500% of the original value in one instance.