Effects of co-trimoxazole, erythromycin, amoxycillin, tetracycline and chloroquine on sperm function in vitro.

This in-vitro study was designed to investigate the effects of commonly prescribed antibiotics on sperm movement characteristics, viability and the ability of spermatozoa to undergo the acrosome reaction. Spermatozoa were obtained by swim-up from normozoospermic semen and cultured for 24 h with increasing concentrations of co-trimoxazole, erythromycin, amoxycillin, tetracycline and chloroquine. Tetracycline at concentrations as low as 2.5 microg/ml led to a significant dose-dependent inhibition in percent rapid-moving spermatozoa, mean path velocity (VAP), straight-line velocity (VSL) and curvilinear velocity (VCL), but at 50 microg/ml tetracycline all spermatozoa were static. Erythromycin had significant effects on rapid movement, VAP, VSL and VCL only at concentrations >100 microg/ml. In contrast, percent rapid-moving spermatozoa was significantly enhanced at low concentrations of chloroquine (5 microg/ml), but significantly inhibited by higher concentrations. Co-trimoxazole did not adversely affect percent rapid-moving spermatozoa below 500 microg/ml, at which concentration movement was decreased by 34%. The mean lateral head displacement (ALH) was significantly enhanced by 5 microg/ml co-trimoxazole and reduced at 1 mg/ml erythromycin. The effects of these drugs were mostly irreversible. Amoxycillin had no effect on sperm movement characteristics over the dose range used, though it inhibited viability at high doses. Viability was significantly reduced at concentrations of all drugs which affect rapid sperm movement; these concentrations of drugs did not appear to affect the ability of spermatozoa to undergo the acrosome reaction. The results from this study, when combined with known effects on spermatogenesis, should facilitate the choice of drugs for the treatment of both genitourinary and unrelated infections in men who are attempting to conceive.