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.