Efficacy of flupentixol and risperidone in chronic schizophrenia with predominantly negative symptoms

The study investigated the non-inferiority of flupentixol compared to risperidone in the treatment of negative symptoms. In addition, the effects of flupentixol on mood and cognitive symptoms were explored. In a randomized, double-blind multicenter study, 144 non-acute schizophrenia patients with predominant negative symptoms were treated with a flexible dose of either flupentixol (4-12 mg/d) or risperidone (2-6 mg/d) for up to 25 weeks. In addition to a non-inferiority analysis, a principal component analysis (PCA) of the PANSS was performed post hoc. Regarding negative symptoms, flupentixol proved to be non-inferior to risperidone. Both drugs improved depressed mood with effect sizes favoring flupentixol. PCA suggested a five-factor structure. Effect sizes for the cognitive factor were up to 0.74 for flupentixol and up to 0.80 for risperidone. EPS scores were rather low and Parkinsonism improved in both groups, but anticholinergic drugs were prescribed significantly more frequently in the flupentixol group, which generally showed significantly more adverse events. Results indicate that the 1st generation antipsychotic flupentixol improves negative, affective and cognitive symptoms in chronic schizophrenia comparable to risperidone. Further studies should confirm the latter using neuropsychological performance tests and should investigate whether tolerability improves with a markedly lower dose range.