Clozapine maintenance therapy in schizophrenia

Abstract

Long-term pharmacotherapy with antipsychotic agents is an important aspect of the management of schizophrenia. In patients responsive to the chosen treatment, maintenance therapy is usually conducted by halving the drug dose that has proven effective during the acute phase. This strategy is suitable for maintaining remission; moreover, it can improve the patients' quality of life. Records from over 1000 patients treated with clozapine during the past 22 years were examined; 782 of these patients were diagnosed with schizophrenia according to the Diagnostic and Statistical Manual of Mental Disorders-Fourth Edition-Text Revision (DSM-IV-TR) criteria (with the modification in early years). From this group, 181 patients were treated with clozapine for at least a year. The mean duration of long-term maintenance treatment with clozapine was 12.2±4.25 years (range: from 14.5 months to 18 years). Clozapine was administered in a daily dose of 50–200 mg (mean: 71.5±14.12 mg). In 76 schizophrenics, treatment was initiated with clozapine, whereas 105 patients were switched over from other treatments after their failure. The control group comprised 152 patients on long-term maintenance therapy with haloperidol. Clozapine administered for long-term maintenance therapy was effective both in paranoid and in catatonic schizophrenia. It also accomplished good results in patients with disorganized or residual schizophrenia, as well as in individuals with schizoaffective psychosis. Relapse rate was similar to that observed in the haloperidol group; however, patient compliance, side-effect profile, and therapeutic efficacy were all superior in the clozapine group. Long-term maintenance therapy with clozapine is successful. Compliance is good; schizophrenic patients are willing to take this atypical antipsychotic for years on end. Clozapine treatment is associated with a low relapse rate and a favorable safety profile.