A comparative trial of haloperidol decanoate and fluphenazine decanoate in chronic schizophrenic patients

A twenty-week double-blind study was conducted to compare the efficacy and side-effect profile of haloperidol decanoate and fluphenazine decanoate, both given four-weekly, in fifty-one chronic schizophrenic patients. The mean dose of fluphenazine decanoate was 84 mg compared to 122 mg for the haloperidol decanoate group--suggesting a potency ratio of 1.0 : 1.4 in this study population. The CPRS sub-scale for schizophrenic symptoms showed a statistically significant improvement (p. less than 0.05) for the haloperidol decanoate group after twenty weeks treatment. A significant difference favouring haloperidol decanoate (p. less than 0.05) was also shown in the CPRS depression sub-scale at the end of the study. No significant between-group differences were found in the incidence of extrapyramidal side-effects at week 20, though consumption of the antiparkinsonian medication orphenadrine was significantly higher (p. less than 0.05) in the fluphenazine decanoate group (mean dose 102 mg) compared to a mean dose of 58 mg for the haloperidol decanoate group. More patients on fluphenazine decanoate gained weight than patients on haloperidol decanoate, but the difference was not statistically significant.