The impact of commonly prescribed drugs on male fertility.

To analyze the impact of commonly used drugs on male fertility, we assessed the clinical characteristics of patients with impaired semen quality while they were taking medication for chronic diseases and after switching therapies. Of 1768 infertile males, 201 patients were taking medications and had impaired semen quality without any seminal tract obstruction, spermatogenic abnormalities or hypogonadotropic hypogonadism. Of these 201 men, a total of 165 had no history of testicular diseases nor abnormalities in any examinations. Amongst them, H1 receptor antagonists were the most common medication taken, followed by antiepileptics and antibiotics. They were divided into two groups: an intervention group (73 patients), who could stop or switch their medications, and a control group (92 patients), who could not. In the intervention group, semen quality improvement rate and conception rate (93% and 85%, respectively) were much higher than those of the control group (12% and 10%, respectively). After switching therapies, the time interval before conception was 7.3 months, which was significantly shorter in asthenozoospermia than oligozoospermia. Our results confirm the potential fertility hazards of commonly used drugs and their reversibility. Moreover, after switching medication, drug-induced asthenozoospermia was cured more rapidly than oligozoospermia, suggesting that further delineation of such differences may help to elucidate mechanisms of spermatogenesis and might facilitate the development of non-hormonal male contraceptive agents.