A double-blind controlled study of intramuscular zuclopenthixol acetate and liquid oral haloperidol in the treatment of schizophrenic patients with acute exacerbation.

We carried out a 9-day double-blind clinical trial comparing intramuscular zuclopenthixol acetate with liquid oral haloperidol in the treatment of 40 newly admitted schizophrenic patients with acute exacerbation. A parallel-group design was used with stratification by sex. Zuclopenthixol acetate (50 to 150 mg) was given intramuscularly every 3 days, whereas liquid haloperidol (10 to 30 mg daily) was given orally three times a day, with supplementary doses of each medication given under double-blind conditions when needed for agitation. No other sedative drugs, including benzodiazepines, were administered. The mean daily dose was 18.9 mg for haloperidol as compared with a mean dose per 3 days of 117.6 mg for zuclopenthixol. The two treatments were found to be equally efficacious on the Brief Psychiatric Rating Scale and Clinical Global Impression Scale. Both drugs induced similar extrapyramidal side effects. However, more tremors were associated with zuclopenthixol as was a tendency for tardive dyskinesia to be unmasked at the end of the injection interval. Sedation was higher with zuclopenthixol acetate than with haloperidol. Serum creatinine phosphokinase levels were not significantly increased after zuclopenthixol injections. The results of this trial suggest that zuclopenthixol acetate given intramuscularly every second to third day offers an alternative to conventional liquid oral haloperidol in the management of acute schizophrenia.