Brexpiprazole dosages of 2-4 mg/day are effective at treating acute schizophrenia patients, a randomized, double-blind, placebo-controlled trial shows.
The investigators studied 623 people living in 10 countries who had been diagnosed with schizophrenia. Patients in the experimental group received varying amounts of brexpiprazole over the course of 6 weeks. The antipsychotic, a serotonin-dopamine activity modulator, acts as a partial agonist at specific serotonin and dopamine receptors.
Eighty-seven of the study’s participants received 0.25 mg/day of the drug. The other 358 participants in the experimental group began with a 1-mg/day dosage. By day 8, 180 of these patients’ dosages were increased to 2 mg/day. The dosages for the remaining 178 patients in the experimental group were upped to 4 mg/day. The 178 individuals in the control group took a placebo.
The entire population was “markedly ill at entry to the study,” as evidenced by Positive and Negative Syndrome Scale (PANSS) and Clinical Global Impressions Scale (CGI) severity scores, according to Dr. Christoph U. Correll and his colleagues.
At the study’s start, the scores were 95.2 and 4.9, respectively. Within 2 weeks of beginning the experiment, the average PANSS score in the 2-mg/day and 4-mg/day groups improved significantly more than the average score in the control group, decreasing by 20.73 for the brexpiprazole 2-mg group and 19.65 for the 4-mg group, compared with a decrease of 12.01 for the control group. This trend continued throughout the remainder of the treatment period.
By week 6, the average effect of the two highest dosages of brexpiprazole on CGI severity scores also was significantly greater than the average effect of the placebo. The PANSS and CGI severity scores only changed minimally for the patients who received 0.25-mg dosages of brexpiprazole.
Although the overall incidence of treatment-emergent adverse events was lower in the entire experimental group than in the control group, akathisia was reported more frequently in the treatment groups, specifically, the 2-mg and 4-mg groups. Psychiatric disorders were the most frequently reported serious adverse events by all groups.
“Brexpiprazole at doses of 2 mg and 4 mg once daily demonstrated statistically significant efficacy compared with placebo and good tolerability for patients with an acute exacerbation of schizophrenia,” Dr. Correll and his associates wrote.
Longer-term research of a more diverse population will need to be conducted to further evaluate the benefits of treating schizophrenia with brexpiprazole and to compare the effectiveness of this drug to first-line antipsychotics, the researchers said.
Read the full study in the American Journal of Psychiatry (2015 April 16 [doi:10.1176/appi.ajp.2015.14101275]).