Patients with schizophrenia may be less likely to stop treatment if prescribed clozapine or the long-acting injectable (LAI) formulations of aripiprazole and paliperidone compared with oral olanzapine, reports a study published today in AJP in Advance. The study made use of data from over 37,000 veterans
“Randomized controlled trials are the gold-standard design used to test the efficacy of antipsychotics but only reflect effectiveness in patients who volunteer for such trials,” wrote Marc Weiser, M.D., of the Stanley Medical Research Institute and colleagues. Weiser and colleagues used the U.S. Department of Veterans Affairs (VA) pharmacy and health databases to compare two outcomes associated with antipsychotic treatment: treatment discontinuation rates and psychiatric hospitalization rate. The analysis included 15 categories: patients taking one of nine oral medications (aripiprazole, clozapine, lurasidone, olanzapine, paliperidone, quetiapine, risperidone, ziprasidone, and oral first-generation antipsychotics), patients taking one of five LAI formulations (aripiprazole, fluphenazine, haloperidol, paliperidone, and risperidone LAIs), and patients receiving polypharmacy. The researchers compared all other medications to olanzapine since it had the lowest discontinuation rate in the seminal Clinical Antipsychotic Trials of Intervention Effectiveness schizophrenia study in 2005. After adjusting for other factors, Weiser and colleagues found that five groups had a lower risk of treatment discontinuation than the olanzapine group: clozapine (57% reduced risk), LAI aripiprazole (29% reduced risk), LAI paliperidone (24% reduced risk), antipsychotic polypharmacy (23% reduced risk), and LAI risperidone (9% reduced risk). Oral quetiapine, oral ziprasidone, oral aripiprazole, oral risperidone, and oral first-generation antipsychotics all had higher risks of discontinuation than olanzapine. “The smaller risk of discontinuation for clozapine may be related to the use of this agent in people who are more likely to be adherent to the monitoring requirements or the increased frequency of visits required to monitor the use of this agent,” Weiser and colleagues wrote. “The smaller risk of clozapine discontinuation may also be related to the lack of alternative treatments for people who fail to demonstrate a robust response to clozapine.” None of the medications were found to reduce the risk of psychiatric hospitalization compared with olanzapine. Several medications were associated with slightly higher hospitalization risk compared with olanzapine: oral first-generation antipsychotics (22% increased risk), LAI paliperidone (27% increased risk), oral lurasidone (33% increased risk), oral quetiapine (36% increased risk), LAI haloperidol (39% increased risk), LAI fluphenazine (40% increased risk), and oral ziprasidone (46% increased risk). To read more on this topic, see the Psychiatric News article “Which Antipsychotics Are Best for Your Patients?” (Image: iStock/Chinnapong)
