Withdrawal symptoms after long-term treatment with low-potency neuroleptics.

Twenty-six chronic schizophrenic outpatients receiving low-potency anticholinergic neuroleptics were switched over periods of up to 2 years to an equivalent dose of high-potency neuroleptics. Of these patients, 85% experienced withdrawal symptoms, mainly insomnia, anxiety, and tensional restlessness. Complete withdrawal of low-potency medication was achieved during the study period in 9 patients only. The mean duration of treatment with low-potency neuroleptics was 15 years and the mean dose was 147 mg chlorpromazine equivalents/day. It is suggested that new symptoms associated with withdrawal of low-potency neuroleptics may lead to overcompliance by patients and difficulty in achieving the minimum therapeutic dosage. Thus, low-potency neuroleptics would not appear suitable for the long-term treatment of most schizophrenic patients.