Avoid taking antacids or stomach acid reducers Tagamet, Pepcid, Axid, Zantac, and others for at least hours after you have taken your dose of ketoconazole. It works by slowing the growth of fungi that cause infection. Ketoconazole Tablets may alter the metabolism of cyclosporine, tacrolimus, and methylprednisolone, resulting in elevated plasma concentrations of the latter drugs. The adverse reactions occurring in percent of adult patients and interneti-apteegi ketoconazole more commonly than in adult patients treated with metformin alone were headache. Mode of Action In vitro studies suggest that ketoconazole impairs the synthesis of ergosterol, which is vital component of fungal cell membranes. Ketoconazole tablets may alter the metabolism of cyclosporine, tacrolimus, and methylprednisolone, resulting in elevated plasma concentrations of the latter drugs.