Outcome and risks of ultra-long-term treatment with an oral neuroleptic drug. Relationship between perazine serum levels and clinical variables in schizophrenic outpatients.

In 33 schizophrenic patients treated continuously as outpatients with perazine over two decades, the rehospitalization rate decreased from 0.58 before treatment to 0.07 during treatment. The intensity of psychopathologic symptoms and the side effects were found to be remarkably low. The high intraindividual constancy of perazine plasma levels and the tight correlation between dose and plasma levels indicated satisfactory patient compliance. Plasma levels amounted to only 25% of those under acute treatment and correlated positively with the severity of the disease. Higher plasma levels coincided with more frequent side effects such as slightly pathologic liver function and moderate impairment of oral glucose tolerance. The results suggest that low-dose maintenance treatment of schizophrenic patients with oral neuroleptics is effective and relatively safe.