First-generation antipsychotic shortages in the United States: Utilization and switching patterns

The United States Food and Drug Administration (FDA) has declared an increasing number of psychotropic shortages, which may adversely affect health outcomes by forcing psychotropic switches or rationing. There is a paucity of literature describing the impact of psychotropic shortages. To describe antipsychotic utilization patterns following FDA-declared antipsychotic shortages or discontinuations. This was a descriptive, pre-post analysis of the Komodo Healthcare Map® between January 2016 and September 2023. Individuals were included if they had a psychotic spectrum disorder diagnosis. Eligible individuals had a prescription drug claim for a first-generation antipsychotic (FGA) during the six months preceding the FDA-declared shortage or discontinuation date (“index date”) and a prescription drug claim for any antipsychotic in the twelve months after the index date. Individuals were excluded if the medication possession ratio (MPR) for their original shortage drug was below 80%, or if they had an inpatient hospitalization within six months of the index date. Switching was the primary outcome of interest and was defined as use of a new antipsychotic during the follow-up period with a MPR of at least 80%. All oral FGAs had at least one manufacturer shortage during the study period, with 95,968 individuals qualifying for inclusion. Most were receiving haloperidol ( n = 52,344, 54.5%) and perphenazine ( n = 16,966, 17.7%). Switching was common among individuals receiving thiothixene (32.8%), trifluoperazine (55.2%), and molindone (100%). Time to first switch ranged from 22 (standard deviation SD: 21) to 103 (SD: 66) days. Shortages of FGAs may influence patients' switching to other agents, including second generation antipsychotics. • First-generation antipsychotics have faced multiple shortages in recent years. • Nearly 10% of patients switched antipsychotics following a declared shortage. • Switching was most common for molindone (100%) and trifluoperazine (55.2%). • Most patients switched to a second-generation antipsychotic after a shortage. • Shortages can change antipsychotic utilization for treating schizophrenia.