Impact of Antipsychotic Treatment Switching in Patients With Schizophrenia, Bipolar Disorder, and Major Depressive Disorder

BACKGROUND: Antipsychotics are commonly used for maintenance treatment of schizophrenia (SZ), bipolar disorder (BP), and major depressive disorder (MDD). Treatment adherence reduces the risk of relapse, but fear of side effects, such as extrapyramidal symptoms (EPS), may prompt medication switching. We evaluated the relapse risk for patients with SZ, BP, and MDD who switched antipsychotics compared with that of those who did not.

DESIGN/METHODS: Medicaid claims from 6 US states spanning 6 years were retrospectively analyzed for antipsychotic switching versus non-switching. For all patients with SZ, BD, or MDD, and for the subset of patients who also had ≥1 EPS diagnosis during the baseline period, times to the following outcomes were analyzed: underlying disease relapse, other psychiatric relapse, all-cause emergency room (ER) visit, all-cause inpatient (IP) admission, and EPS diagnosis.

RESULTS: Switchers (N=10,548) had a shorter time to disease relapse, other psychiatric relapse, IP admissions, ER visits, and EPS diagnosis (all, log-rank P < 0.001) than non-switchers (N=31,644). Switchers reached the median for IP admission (21.50 months) vs non-switchers (not reached) and for ER visits (switchers, 9.07 months; non-switchers, 13.35 months). For disease relapse, other psychiatric relapse, and EPS diagnosis, < 50% of patients had an event during the 2-year study period. Subgroup analysis of those with ≥1 EPS diagnosis revealed similar outcomes.

CONCLUSIONS: Disease or other psychiatric relapses, all-cause ER visits, IP admissions, and EPS diagnosis occurred earlier for switchers than for non-switchers, suggesting that switching is associated with an increased risk of relapse in patients with SZ, BP and MDD.

This poster was presented at the 32nd annual Psych Congress, held Oct. 3-6, 2019, in San Diego, California.