Iminodibenzyl class antipsychotics for schizophrenia: a systematic review and meta-analysis of carpipramine, clocapramine, and mosapramine

BACKGROUND We conducted a meta-analysis of the iminodibenzyl antipsychotics carpipramine, clocapramine, and mosapramine, which are classified as second-generation antipsychotics (SGAs) for schizophrenia treatment. METHODS We searched data that had been published in PubMed, the Cochrane Library databases, PsycINFO, CiNii, and the Japan Medical Abstracts Society up to August 29, 2014. Randomized controlled trials that compared iminodibenzyl antipsychotics with other antipsychotics in patients with schizophrenia were included. Odds ratios and standardized mean differences were evaluated. RESULTS We included four randomized controlled trials on carpipramine (number of patients [n]=290), six on clocapramine (n=1,048), and five on mosapramine (n=986) in the meta-analysis. There were no significant differences in the response rates or in the discontinuation rates either between carpipramine and the other pooled antipsychotics or between clocapramine and the other pooled antipsychotics. On the Positive and Negative Syndrome Scale, mosapramine's positive subscale scores were superior to those of the other pooled antipsychotics (standard mean of difference =-0.22); however, on that same scale, there were no significant differences in total scores, negative scores, general subscale scores, response rates, or the discontinuation rates between mosapramine and the other pooled antipsychotics. Furthermore, the incidences of extrapyramidal symptoms and of hyperprolactinemia were significantly greater with mosapramine than with the other pooled antipsychotics. CONCLUSION The pharmacological profiles of carpipramine and clocapramine, which are classified as SGAs, were similar to those of first-generation antipsychotics because there were no significant differences in efficacy and safety outcomes. However, mosapramine was associated with a greater risk of extrapyramidal symptoms and hyperprolactinemia than the other SGAs were, although it may be beneficial for the improvement of positive symptoms.