Adverse effect of paroxetine on sperm.

Objective: To assess the effects of a selective serotonin reuptake inhibitor on semen parameters.

Design: Prospective study.

Setting: Academic medical center.

Patient(s): Thirty-five healthy male volunteers, 18-65 years old.

Intervention(s): Paroxetine administration for 5 weeks.

Main Outcome Measure(s): Serum hormone levels, semen analyses, percent sperm DNA fragmentation, and questionnaire assessment of sexual function assessed before, during, and 1 month after drug administration.

Result(s): Mean sperm DNA fragmentation was significantly higher for men while on paroxetine (30.3%) versus baseline (13.8%). Before paroxetine, 9.7% of patients had a terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) score>or=30% compared with 50% at week 4 of treatment. The odds ratio (OR) of having abnormal DNA fragmentation while taking paroxetine was 9.33 (95% confidence interval, 2.3-37.9]. Multivariate logistic regression correcting for age and body mass index confirmed this correlation (OR, 11.12). Up to 35% of men noted significant changes in erectile function and up to 47% of men reported ejaculatory difficulties on medication. Recovery to near-normal sexual function was noted after stopping treatment. Standard semen parameters were not significantly altered during paroxetine treatment.

Conclusion(s): In men with normal semen parameters, paroxetine induced abnormal sperm DNA fragmentation in a significant proportion of subjects, without a measurable effect on semen parameters. The fertility potential of a substantial number of men on paroxetine may be adversely affected by these changes in sperm DNA integrity.