Efficacy and safety of cariprazine augmentation in patients treated with clozapine: a pilot study

Cariprazine, a novel antipsychotic drug, is a partial agonist of dopamine D2/D3 receptors with preferential binding to the D3 receptor. There has been an increasing interest in cariprazine augmentation to clozapine; however, the evidence thus far has been only limited to case reports and case series.

To evaluate the efficacy and safety of the augmentation of clozapine with cariprazine in patients with sub-optimal treatment response.

Demographic and clinical information of the study population were collected from the electronic records and PANSS scale administered at baseline and 3 months. Tolerability and discontinuation reasons where applicable were also recorded.

Ten patients (four men and six women) with a mean age of 36.5 years (range = 26-45) were included. Reasons for cariprazine initiation included inadequate treatment response, persistent negative symptoms and/or tolerability issues with clozapine or previous augmentation options. Two patients discontinued cariprazine within the first 6 weeks due to restlessness and poor response, respectively. There was a significant reduction in the median total PANSS score from baseline to 3 months (from 59 to 22.5, p < 0.05), median positive PANSS score (from 11.5 to 5.5, p < 0.05) and in the median negative PANSS score (from 15.5 to 3, p < 0.05) which correspond to a 48%, 33.8% and 65.8% mean score reduction, respectively.

This is the first pilot study evaluating the effectiveness of clozapine augmentation. The preliminary evidence suggests that this may be a safe and effective practice in patients failing to adequately respond to or tolerate clozapine and/or previous augmentation strategies.