Polypharmacy and clinical outcomes in geriatric patients with metastatic hormone-sensitive prostate cancer treated with androgen receptor pathway inhibitors

ObjectiveThis study aimed to evaluate the prevalence of polypharmacy and its association with clinically significant adverse events in geriatric patients (≥65 years) with metastatic hormone-sensitive prostate cancer (mHSPC) receiving androgen receptor pathway inhibitors (ARPis) in routine clinical practice.MethodsThis retrospective observational study included 186 male patients with mHSPC who received ARPi therapy between March 2024 and January 2026. Patient data were obtained from electronic health records. Polypharmacy was defined as the concurrent use of five or more medications, including ARPi. Adverse events were graded based on Common Terminology Criteria for Adverse Events (CTCAE) Version 5.0.Results97.3% of 186 patients were using at least one medicine simultaneously with an ARPi, with a median of seven concomitant medicines. The prevalence of polypharmacy was found to be 55.4%. The most commonly prescribed drug classes included analgesics, antihypertensives, lipid-lowering agents, and antidiabetics. The most frequent Grade 3-4 adverse events were anemia (11.8%), fatigue (10.2%), and hypokalemia (9.1%). Liver enzyme elevations were observed more frequently in patients receiving enzalutamide whereas those treated with abiraterone acetate were more likely to develop metabolic and electrolyte abnormalities, including anemia, hypokalemia, and elevated creatinine kinase levels.ConclusionsPolypharmacy is highly prevalent among geriatric patients receiving ARPi for mHSPC and may contribute to the development of clinically significant toxicities and adverse events.