To understand the relationship between common urologic medications phosphodiesterase-5 inhibitors (PDE5i) and anticholinergics (AC) and risk of dementia onset in men who underwent different primary treatments for prostate cancer.

Patients (>50years) with prostate cancer (1998-2022) without Alzheimer’s disease or related dementias were selected from Cancer of the Prostatic Strategic Urologic Research Endeavor Registry. Minimum medication use was 3months. Fine-Gray regression was performed to determine the association between medication exposure and dementia onset ≥12months after primary treatment in men matched on age, race, comorbid conditions, smoking, and type of clinical site, with competing risk of death.

Among 5937 men (53% PDE5i; 14% AC), PDE5i users were younger (63 vs 70, P < .01) with less CAD, CVA, DM (all P < .01); AC users were older (68 vs 66, P < .01) with higher incidence of comorbidities (P < .01). Median months of use was 24.3 (IQR 12.1, 48.7) for PDE5i and 12.2 (IQR 6.1, 24.3) for AC users.

Cumulative incidence of Alzheimer’s disease or related dementias was 6.5% at 15years. PDE5i (P = .07) and AC (P = .06) were not associated with dementia regardless of primary treatment modality.

In this retrospective cohort study, PDE5i and AC use do not appear independently associated with risk of dementia. Notably, our cohort was generally healthy and younger which may limit our ability to detect significance. We recommend prospective investigation into association between PDE5i and dementia and advise continued judicious stewardship of AC in older patient populations.