Kohagra Drug Interactions

Sildenafil or other phosphodiesterase type-5 inhibitors may potentiate the hypotensive effects of organic nitrates, and are therefore contraindicated in patients receiving such drugs. Sildenafil may also enhance the hypotensive effect of nicorandil and use of the two drugs together should be avoided. Symptomatic hypotension may also occur when phosphodiesterase type-5 inhibitors are given with alpha blockers. Drugs that inhibit cytochrome P450 isoenzyme CYP3A4, such as cimetidine, delavirdine, erythromycin, Itraconazole, and ketoconazole, may reduce the clearance of phosphodiesterase type-5 inhibitors, necessitating a reduction in dosage. Plasma concentrations of phosphodiesterase type-5 inhibitors are significantly increased by HIV-protease inhibitors, and particularly so by ritonavir-booster regimens. Grape fruit should be avoided with sildenafil or other phosphodiesterase type-5 inhibitors as it may increase their plasma concentrations. Inducers of CYP3A4, such as rifampicin, are likely to decrease plasma concentrations of phosphodiesterase type-5 inhibitors.