Persistent sexual side effects of finasteride: could they be permanent?

INTRODUCTION

Finasteride has been associated with sexual side effects that may persist despite discontinuation of the medication. In a clinical series, 20% of subjects with male pattern hair loss reported persistent sexual dysfunction for ≥6 years, suggesting the possibility that the dysfunction may be permanent. These subjects also reported a wide range of symptoms including changes in cognition, ejaculate quality, and genital sensation. Other medications have been associated with irreversible neurological effects, such as phenothiazines with tardive dyskinesias.

AIM: To prospectively study whether the persistent sexual side effects associated with finasteride resolve or endure over time.

METHODS

Subjects (N = 54) with persistent sexual side effects associated with finasteride were reassessed after 9-16 months (mean 14 months). All subjects were otherwise healthy young men without any baseline sexual dysfunction, medical conditions, psychiatric conditions, or use of oral prescription medications prior to taking finasteride for male pattern hair loss.

MAIN OUTCOME MEASURE: Scores from the Arizona Sexual Experience Scale (ASEX).

RESULTS

The participation rate was 81%. At reassessment persistent sexual side effects continued to be present in 96% of subjects. According to the ASEX scores, 89% of subjects met the definition of sexual dysfunction. Neither the length of finasteride use nor the duration of the sexual side effects correlated to changes in scores of sexual dysfunction.

CONCLUSION

In most men who developed persistent sexual side effects (≥3 months) despite the discontinuation of finasteride, the sexual dysfunction continued for many months or years. Although several rat studies have shown detrimental changes to erectile function caused by 5 alpha reductase inhibitors, the persistent nature of these changes is an area of active research. Prescribers of finasteride and men contemplating its use should be made aware of the potential adverse medication effects.