Study of penfluridol and chlorpromazine in the treatment of chronic schizophrenia.

This study presents data on the use of penfluridol, a once-a-week orally administered, antipsychotic agent, in the treatment of chronic schizophrenic patients. Fifty-nine patients participated in the initial dose titration segment during which doses of penfluridol were adjusted weekly until the patients' condition became stabilized. The starting dose did not exceed 60 mg per week, and the maximum weekly dose did not exceed 140 mg. Forty-one of these patients continued on to participate in a double-blind comparison of penfluridol with chlorpromazine. Maximum doses did not exceed 140 mg per dose per week for penfluridol and 7350 mg per week for chlorpromazine in the double-blind segment. Patients were abruptly switched from their previous neuroleptic medication to penfluridol without loss of control. Side effects, mainly extrapyramidal in nature, were readily alleviated with benztropine mesylate. Penfluridol, administered orally once a week, appeared to be well tolerated; it was comparable to daily chlorpromazine in treating and maintaining schizophrenic patients.