Polypharmacy, commonly defined as the concurrent use of ≥5 medications, is associated with adverse outcomes, but comprehensive data on its prevalence and temporal trends in patients with atrial fibrillation (AF) are limited.

We conducted a nationwide retrospective cohort study using FinACAF (Finnish AntiCoagulation in Atrial Fibrillation) cohort, including all patients with incident AF between 2007 and 2018. Data were retrieved from national health care and prescription registers, covering all levels of care. Medication use was assessed within 120 days before and after AF diagnosis. Polypharmacy was defined as the use of ≥5 medications. Temporal trends and associations between baseline characteristics and drug count were analyzed using linear regression.

Among 229 565 patients with incident AF (mean age 72.7 years, SD 13.2; 50% women), the mean number of medications after diagnosis was 6.0 (SD 3.9). Overall, 63.1% of patients were exposed to polypharmacy, and 17.7% used ≥10 medications. Polypharmacy was more common among older patients and those with comorbidities, especially hypertension and diabetes. From 2007 to 2018, the mean number of drugs increased modestly (from 5.5 to 6.2, P<0.001). The most pronounced increases were seen in anticoagulant and cardiovascular drug use.

Polypharmacy is highly prevalent among patients with AF in Finland and has increased over time. These findings underscore the need for holistic, patient‐centered management strategies to optimize outcomes in this multimorbid population.