The urologic impact of long-term finasteride 1-mg use for androgenic alopecia: a matched-cohort database analysis

Since its approval in 1997, finasteride-1 mg (F1) can be taken daily to treat androgenic alopecia (AA) by reducing serum dihydrotestosterone (DHT). When finasteride is prescribed at the 5 mg dosage, the DHT reduction is known to affect sexual function, reduce serum prostate-specific antigen (PSA) levels and treat benign prostatic hyperplasia (BPH). However, there is no literature on the urologic function of men using long-term F1. Thus, we aimed to address this knowledge gap by analyzing a database for the impact of F1 on urologic function.

Using the Truveta database, we identified men aged 18 + diagnosed with AA per International Classification of Diseases (ICD) coding, with at least 90 days of F1 use and ≥ 5 years of follow-up. Exclusions included patients with a history of anti-depressant usage, prior diagnosis (Dx) or treatment (Tx) of erectile dysfunction (ED), BPH, or prostate cancer (PC). A control cohort with AA but no F1 use was matched based on age, race, ethnicity, and marital status. We compared Dx rates, Tx rates, and time to Dx or Tx using Chi-square and Kruskal-Wallis Rank sum tests. Survival analysis was performed with restricted mean survival time.

We identified 3470 patients with long-term F1 use and 3470 matched patients with AA but no F1 use. The average age for the F1 group was 40.59 and 39.75 for the control. Average F1 use duration was 2011.5 days. Median follow-up was 2554.7 days for the F1 group, and 3129.5 days for the control. The F1 group had higher phosphodiesterase type 5 inhibitor (PDE5i) prescription rate (13.6% vs. 10.5%, p < 0.001) and earlier prescription by 238.6 days (95% CI -304.3, -172.9, p < 0.0001). The control group had a higher -blocker prescription rate (4.4% vs. 2.9%, p = 0.001). There were no significant differences in ED diagnosis, BPH Dx rates or time-to BPH diagnosis or α-blocker prescription. The F1 group had lower elevated PSA Dx and PC Dx rates (2.9% vs. 4.4%, p < 0.001; 0.9% vs. 1.8%, p = 0.001).

Though ED diagnosis did not differ significantly, patients on long-term F1 for AA were more likely to be prescribed PDE5i and sooner by approximately 230 days, compared to non-F1 users. F1 did not significantly affect BPH Dx or Tx rates. F1 use was associated with decreased PC and elevated PSA Dx rates. More research on urologic effects of chronic F1 use in AA patients is needed.