Oral phosphodiesterase type 5 inhibitors and male reproductive potential: an overview

Phosphodiesterase type 5 inhibitors (PDE5Is), due to their efficacy and tolerable profile for more than 2 decades,are considered a good addition to the available treatments in patients with erectile dysfunction (ED). We sought to assess the possible influence of oral PDE5Is on male human reproduction. A literature review was performed in several databases, including the PubMed/Medline database, Scopus, Cochrane Library, EMBASE, Academic Search Complete, and Egyptian Knowledge Bank databases. The keywords/search terms were "PDE5Is," "sildenafil," "vardenafil," "tadalafil," or "avanafil," combining and crossing them with "male infertility," "semen," "reproductive hormones," or "sperm." Overall, 101 articles were selected. After removal of duplicates and animal studies, 75 articles were finally subjected to review covering the different items related to male human reproduction, including effects of PDE5Is on different parameters of semen or reproductive hormones, as uses of PDE5Is in cases related to distinctive male factor infertility, such as ED, temporary ED, or ejaculatory failure alongside assisted reproduction (AR) procedures, and ejaculatory dysfunction in spinal cord lesions. We found 26 articles that addressed the direct effects of PDE5Is on semen and reproductive hormonal profiles, 16 in vivo studies and 10 in vitro studies. Oral PDE5Is have in general a stimulatory effect on sperm motility, while other semen parameters and reproductive hormonal profiles showed varied outcomes. Such effects are more pronounced with a long-term daily regimen than with an on-demand regimen. However, it seems that the best-controlled studies suggested no change in the sperm quality of male reproductive potential. Oral PDE5Is have in general stimulatory effects on sperm motility, while other semen parameters and hormone profiles showed varied results. In addition, oral PDE5Is have played a useful role in conditions related to distinctive male factor infertility, such as ED, temporary ED, ejaculatory failure alongside AR, and ejaculatory dysfunction in spinal cord lesions.