GASTROINTESTINAL DISTURBANCES ASSOCIATED WITH WITHDRAWAL OF ATARACTIC DRUGS.

The psychological effects of abrupt withdrawal of ataractic drugs have been studied by others. Physical symptoms also occur under such circumstances and include abdominal pain, nausea and vomiting. Forty patients were divided into four groups of 10, each group receiving one of the following drugs: chlorpromazine, thioridazine, perphenazine or chlorprothixene. This medication was then suddenly withdrawn. In each of the chlorpromazine and thioridazine groups, three patients had gastrointestinal symptoms within 48 hours, lasting one to eight days. One patient on chlorprothixene, 450 mg. daily, experienced symptoms for six days. Perphenazine withdrawal produced no such symptoms. Thioridazine has little antiemetic action but perphenazine is prescribed for vomiting; hence it seems unlikely that the reported symptoms are due to a rebound action on the vomiting centre.These findings are relevant to the situation of withdrawal of ataractics prior to administration of anesthetics and to drug studies involving cross-over from an active compound to a placebo. The increasing use of ataractics suggests that this additional diagnostic possibility should be considered in the presence of obscure gastrointestinal symptoms.