Disproportional signal of sexual dysfunction reports associated with finasteride use: A pharmacovigilance analysis of VigiBase
David-Dan Nguyen1,2, Peter Herzog1, Eugene B. Cone1, Muhieddine Labban1, Kevin C. Zorn3, Bilal Chughtai4, Shehzad Basaria5, Dean Elterman6, Quoc-Dien Trinh1, Naeem Bhojani3.
1Division of Urological Surgery and Center for Surgery and Public Health, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA, United States; 2Faculty of Medicine and Health Sciences, McGill University, Montreal, QC, Canada; 3Division of Urology, Centre hospitalier de l’Université de Montréal (CHUM), Université de Montréal, Montreal, QC, Canada; 4Department of Urology, Weill Cornell Medical College/New York Presbyterian, New York, NY, United States; 5Research Program in Men’s Health: Aging and Metabolism, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA, United States; 6Division of Urology, University Health Network (UHN), University of Toronto, Toronto, ON, Canada
Introduction: Finasteride, a 5α-reductase inhibitor, is used in the management of alopecia and benign prostatic hyperplasia (BPH). Previous reports suggest that some men taking finasteride experience a constellation of adverse events, including sexual dysfunction. We investigated the association of sexual dysfunction with finasteride use
Methods: We conducted a pharmacovigilance study using VigiBase, the World Health Organization's global database of individual case safety reports. We used the reporting odds ratio (ROR), a surrogate measure of association used in disproportionality analysis, with 95% confidence intervals (CI). Extensive sensitivity analyses included stratifying by indication (BPH and alopecia) and age (<45 and ≥45); comparing finasteride signals to those of drugs with different mechanisms but similar indications (minoxidil for alopecia and tamsulosin for BPH); comparing finasteride to a drug with a similar mechanism of action (dutasteride); and comparing reports of sexual dysfunction before and after 2012.
Results: We identified 7700 reports of sexual dysfunction in finasteride users. There was a significant disproportionality signal for sexual dysfunction (ROR 50.30, 95% CI 49.03–51.60) linked to finasteride use. All sensitivity analyses met the threshold of signal significance (Table 1). Patients under the age of 45 (ROR 65.73, 95% CI 61.83–69.88) and alopecia patients (ROR 33.62, 95% CI 25.22–44.82) had larger signals than older patients (ROR 30.43, 95% CI 27.12–34.15) and those with BPH (ROR 1.74, 95% CI 1.47–2.07). A signal was detected for minoxidil (ROR 1.92, 95% CI 1.54–2.38).
Conclusions: We detected disproportional signals of sexual dysfunction linked with finasteride use. Despite sexual dysfunction being more prevalent in older BPH patients, we detected larger signals of sexual dysfunction in young alopecia patients. Sensitivity analyses suggest that reports of sexual dysfunction linked with finasteride use may be confounded by indication (young alopecia patients may be more likely to experience sexual dysfunction) and by stimulated reporting. However, confounding alone does not account for the totality of the signal observed in young patients with alopecia, considering the large difference in signal size between finasteride and minoxidil.
