BACKGROUND Three studies compared olanzapine and haloperidol given orally in maintenance therapy for schizophrenia and related psychoses.
METHOD Data were from double-blind extensions of acute studies. The subjects met criteria for schizophrenia, schizophreniform disorder or schizoaffective disorder. Subjects had responded to acute therapy (Brief Psychiatric Rating Scale total score decreased > or = 40% from baseline (Studies 1, 2, and 3) or was < or = 18 (Studies 1 and 2)) and were out-patients at their last acute phase visit. Relapse was defined as hospitalisation for psychopathology. Subjects treated with olanzapine in the three studies were pooled to form the olanzapine group and subjects treated with haloperidol were pooled to form the haloperidol group.
RESULTS Olanzapine-treated subjects experienced less relapse (P = 0.034). The Kaplan-Meier estimated one-year risk of relapse was 19.7% with olanzapine and 28% with haloperidol.
CONCLUSION Olanzapine was superior to haloperidol in the maintenance therapy of schizophrenia and related psychoses.
DECLARATION OF INTEREST This work was sponsored by Eli Lilly and Company.