Prevalence of concomitant medications among patients with schizophrenia prescribed atypical antipsychotics

This work was sponsored by Sumitomo Pharma America Inc. Introduction Patients with Schizophrenia are often prescribed concomitant medications to manage their condition, increasing polypharmacy. The prevalence of concomitant medications is not well established. This study evaluated the annual prevalence of concomitant medications among patients with schizophrenia who were prescribed atypical antipsychotics (AAPs). Methods This retrospective study was conducted using the PharMetrics database (01/2019 – 12/2021) and included patients diagnosed with schizophrenia. The concomitant drugs prescribed were labeled at the drug class (GPI2) and generic drug level. Prevalence for drug class and each drug was calculated as a percentage of patients who were prescribed ≥1 of the agent within the given year. Results This study included 12,360; 13,242 and 14,780 patients for the years 2019-21, respectively. These patients had a mean age of 43.5 - 45.4 years and they were predominantly male and commercially insured. Antidepressants were the most prevalent concomitant medication prescribed (2019: 61.2%, 2020: 61.2%, 2021: 62.0%). Other highly prevalent drug classes identified were - anticonvulsants (2019: 44.2%, 2020: 44.5%, 2021: 45.0%), antianxiety agents (2019: 36.3%, 2020: 37.6%, 2021: 38.9%), antihyperlipidemics (2019: 26.3%, 2020: 28.1%, 2021: 30.7%), antihypertensives (2019: 25.7%, 2020: 27.2%, 2021: 28.1%), antiparkinson agents (2019: 61.2%, 2020: 61.2%, 2021: 62.0%), anticholinergics (2019: 61.2%, 2020: 61.2%, 2021: 62.0%) and analgesics (2019: 61.2%, 2020: 61.2%, 2021: 62.0%). At the individual drug level, benzotropine mesylate, atorvastatin, lorazepam, gabapentin, and metformin were the most prevalent prescribed concomitant medications. Conclusions These results indicate a high prevalence of concomitant antidepressants, antihyperlipidemics, antihypertensives and anticholinergics among patients with schizophrenia who are prescribed AAPs.