A comparison of parenteral loxapine and haloperidol in hostile and aggressive acutely schizophrenic patients.

In a parallel groups, double-blind study, 54 acutely psychotic schizophrenics were given loxapine or haloperidol parenterally for 24 to 72 hours, then orally for a total study period of up to 10 days. Dosage ratios of loxapine to haloperidol ranged from a minimum of 2.7:1 to a maximum of 4.4:1. Both groups showed significant and rapid improvement from baseline. Forty-eight percent of the loxapine patients and 33% of the haloperidol patients achieved and maintained a global severity of illness rating of mild or better. By the end of the study, 84% of the loxapine patients and 63% of the haloperidol patients had achieved an improvement rating of moderate or marked. This difference approached significance (p less than .10). The most frequently reported adverse experiences were dystonic reactions and akathisia. The number and severity of adverse experiences did not differ significantly between drug groups. Intramuscular loxapine was at least as effective as haloperidol in the initial management of hostile and aggressive schizophrenic patients. The maintenance of therapeutic response after conversion to oral concentrate was comparable with the two drugs.