Certain antipsychotic polytherapies, including aripiprazole and clozapine, are associated with a lower risk of psychiatric rehospitalization in patients with schizophrenia, according to Jari Tiihonen, MD, PhD, of the Karolinska Institute in Stockholm, and his associates.
The study population included a total of 62,250 patients from the Finnish Hospital Discharge register who were treated for schizophrenia in the inpatient setting from 1972 to 2014. The median patient age was 45.6 years and the median length of follow-up was 14.1 years. Over the study period, 58.8% of this cohort were readmitted for psychiatric inpatient care, 67.2% used antipsychotic polypharmacy during the follow-up, and 57.5% were exposed to antipsychotic polypharmacy for at least 90 days, Dr. Tiihonen and his associates wrote in JAMA Psychiatry.
The combination of aripiprazole and clozapine was associated with the lowest risk of psychiatric rehospitalization, compared with those who received no therapy (hazard ratio, 0.42, 95% confidence interval, 0.39-0.46). Clozapine alone was the most effective antipsychotic monotherapy (HR, 0.49; 95% CI, 0.47-0.51), and when aripiprazole/clozapine was compared with clozapine alone, the polytherapy was significantly more effective (HR, 0.86; 95% CI, 0.79-0.94).
The difference between aripiprazole/clozapine and clozapine alone was even greater in patients who initially were hospitalized for their first episode of schizophrenia (HR, 0.78; 95% CI, 0.63-0.96). Overall, any antipsychotic polypharmacy was associated with a 7%-13% lower risk of hospitalization, compared with any monotherapy; , the authors noted.
“It should be acknowledged that statements about a preferential use of antipsychotic monotherapy for maintenance treatment of schizophrenia lack evidence, and that currently available evidence – although gathered with few nonrandomized cohort studies that have their own limitations – indicates the opposite,” they concluded.
Dr. Tiihonen and several of his associates reported numerous conflicts of interest.
SOURCE: Tiihonen J et al. JAMA Psychiatry. 2019 Feb 20. doi: 10.1001/jamapsychiatry.2018.4320.