Parkinsonian Reactions Following Chlorpromazine and Reserpine

Abstract

Chlorpromazine and reserpine, in the large doses used in the treatment of psychiatric patients, produce striking side-effects in a fairly large percentage of patients. One of these reactions found after chlorpromazine as well as after reserpine medication is a Parkinsonian syndrome. Its occurrence seems to be related to dosage and the duration of medication and is reported in about 10% of the patients after chlorpromazine administration. The incidence reported in the literature extends from no cases to the statement that "all patients who are on large doses of thorazine ® for any length of time show some signs of basal ganglion dysfunction."¹We found that the incidence of 9.3% reported by Freyhan,^1awith 5.1% requiring termination of the treatment and 4.2% not requiring termination, is a figure corresponding to our own observations. Parkinsonian reactions during reserpine medication were noted by others—for example, by Kline and Stanley²in