A pilot study of the role of prophylactic antiparkinson treatment during neuroleptic therapy.

The authors administered haloperidol 4.5 mg t.i.d. to 33 drug-free schizophrenic patients. Ten patients did not receive anything else (group HPL), while ten patients received procyclidine 5 mg t.i.d., and 13 patients were given promethazine 25 mg t.i.d. (groups HPRC and HPRM respectively) in addition. Seven patients dropped out of the HPL group and three out of the HPRM group, but none out of the HPRC group. These drop outs were due to the development of early extrapyramidal side effects, which were absent in the HPRC group. The findings suggest that antiparkinson prophylaxis is useful during commencement of therapy with high-potency neuroleptic agents.