androstenedione and DHEA Direct testicular damage Busulfan Nitrosurea Vincristine Ethanol Block testosterone synthesis Ketoconazole Spironolactone Metronidazole Etomidate Block androgen action Flutamide Bicalutamide Finasteride Cyproterone Zanoterone Cimetidine Ranitidine Spironolactone Displace estrogen from SHBG Spironolactone Ethanol. best time to take clomid for men After no success, their doctor suggested IVF, but the couple felt it was too stressful, time-consuming and expensive, so they opted out.