April 1978

Are Prophylactic Antiparkinson Drugs Necessary?A Controlled Study of Procyclidine Withdrawal

Author Affiliations

From the Department of Psychiatry, College of Physicians and Surgeons, Columbia University, and the New York State Psychiatric Institute, New York (Drs Rifkin, Quitkin, Klein), and the Department of Psychiatry, Long Island Jewish-Hillside Medical Center, Glen Oaks, New York (Drs Kane and Struve).

Arch Gen Psychiatry. 1978;35(4):483-489. doi:10.1001/archpsyc.1978.01770280093010

• Of 55 aftercare patients receiving long-term treatment with antipsychotic and antiparkinson (AP) drugs, 37 were switched to being given placebo, and 18 remained on a regimen of procyclidine hydrochloride. The dose of antipsychotic was kept constant. After three weeks extrapyramidal side effects (EPS) developed in 54% of those patients receiving placebo and in none of those receiving procyclidine (P <.002): Twenty-seven percent of the placebo group had EPS without akinesia, and in the same percentage akinesia developed (P =.003). We believe the risk-benefit ratio favors the routine use of AP drugs for prophylaxis and maintenance so as to avoid misdiagnosing as psychopathology, unspontaneity due to akinesia, and to reduce unreliable pill-taking due to EPS.