Avoiding Toxins Including Spermatotoxic Medications

Gillian Stearns, MD; Paul J. Turek, MD


Semin Reprod Med. 2013;31(4):286-292. 

In This Article


Calcium Channel Blockers

Calcium has been shown to be a primary determinant of sperm function, involved in both the capacitation and acrosome reactions. Functional studies have shown that calcium channels exist on mammalian sperm, and other studies have observed that calcium fluxes help mediate oocyte fertilization.[35,36] CatSper, a pH-regulated, calcium-selective ion channel, and KSper (Slo3) are core regulators of sperm tail calcium entry and sperm hyperactive motility.[37] In animal models, administration of calcium channel blockers results in decreased sperm count and motility, a dose-dependent decrease in testis size and a maturation arrest pattern of sperm production.[35] Observed decreases in testosterone levels with preserved LH levels have also been reported.[38] The uniqueness of the calcium channels found on sperm makes them excellent potential targets for male contraception.[37]


Spironolactone, a potent antiandrogen, affects spermatogenesis in two ways: decreasing sexual desire and erections and impairing semen quality.[3] It prevents binding of DHT to its receptor and impairs 17-hydroxylase in steroid biosynthesis, decreasing serum testosterone and facilitating estrogen conversion.[3,18] However, the amount of drug that appears necessary to effectively inhibit 17-hydroxylase is greater than that found in routine clinical doses of spironolactone.[18] Indeed, in one study, five men who received 400 mg/day of spironolactone showed no change in testosterone, prolactin, LH, or FSH levels.[39]