Once weekly pimozide versus fluphenazine decanoate as maintenance therapy in chronic schizophrenia.

In a double blind trial, 28 male chronic schizophrenic in-patients received either pimozide, given once weekly, or fluphenazine decanoate, given mostly once fortnightly. There was no difference in relapse rates over nine months. However, three-quarters of the patients on pimozide who completed the trial developed at least mild tardive dyskinesia. All patients on pimozide lost weight, the average loss being 5.4 kg (12 lbs). Plasma pimozide levels suggested satisfactory drug compliance. Plasma prolactin levels confirmed that in the pimozide group there was fluctuating dopamine receptor antagonism, while in the fluphenazine group average plasma prolactin levels throughout most of the interval between injections were at the upper limit of normal.