A randomized, double-blind comparison of risperidone versus low-dose risperidone
plus low-dose haloperidol in treating schizophrenia.
Author(s): Lin CH, Kuo CC, Chou LS, Chen YH, Chen CC, Huang KH, Lane HY.
Affiliation(s): Kai-Suan Psychiatric Hospital, Kaohsiung, Taiwan.
Publication date & source: 2010, J Clin Psychopharmacol. , 30(5):518-25
Monotherapy is recommended for schizophrenia treatment, but the risk-benefit
issue of antipsychotic drug combination (except for clozapine) remains unclear.
Risperidone, an atypical antipsychotic drug, has a lower incidence of
extrapyramidal syndrome but higher risks of prolactinemia and metabolic syndrome
than haloperidol, a typical agent. This study compared efficacy and safety of
risperidone monotherapy versus low-dose risperidone plus low-dose haloperidol in
schizophrenia. In this 6-week, double-blind study, patients were randomized to
the combination group (2-mg/d risperidone plus 2-mg/d haloperidol, n = 46) or the
monotherapy group (4-mg/d risperidone, n = 42). Efficacy assessments included
Clinical Global Impression-Severity, Positive and Negative Syndrome Scale and
subscales, Calgary Depression Scale, Global Assessment of Functioning, and
Medical Outcomes Study Short-Form 36. Safety was rigorously monitored. Response
was defined as 30% reduction in the Positive and Negative Syndrome Scale total
score. The 2 treatment groups were similar in (1) demographic and clinical
characteristics at baseline, (2) response rate, and (3) improvement in various
psychopathological measures and quality of life at end point. The monotherapy
group had a higher increase in prolactin levels (P = 0.04) and Simpson-Angus
Scale scores (P = 0.04) and a higher percentage of biperiden use (P = 0.045).
There were no significant between-group difference in changes in weight, vital
signs, corrected QT interval, liver/renal function, fasting glucose level, and
lipid profiles. The findings suggest that risperidone monotherapy may yield
higher prolactin levels than a combination of low-dose risperidone plus low-dose
haloperidol. The 2 treatment groups are similar in efficacy, life quality, and
other safety profiles. Future long-term studies are warranted.
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