12-month study of haloperidol decanoate in chronic schizophrenic patients.

239 psychotic patients entered a 52-week open study comparing the efficacy and safety of intramuscular haloperidol decanoate, injected once every 4 weeks, with that of their previous maintenance therapy. Haloperidol decanoate, given at a medium monthly dose of 100 mg provided a suitable substitute for oral neuroleptic mono- and polytherapy and intramuscular fluphenazine decanoate. Stabilization or slight improvement was observed for all ten symptoms selected from the BPRS. The drug provoked a low incidence of side-effects allowing reduction of antiparkinsonian medication and there were no significant haematological or biochemical changes.