Iqnyde 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. Generally, the patient should be stabilised on alpha blocker therapy before the phosphodiesterase type-5 inhibitor is started at a low dose and adjusted according to response.
Drugs that inhibit the cytochrome P-450 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-boosted regimens. Such combinations should not be given unless absolutely essential.
Grapefruit juice should be avoided with slldenafil 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.
Plasma concentration of sildenafil reduced by Bosentan.
Plasma concentration of sildenafil possibly increased by clarithromycin, telithromycin and erythromycin.
Sildenafil may enhance hypotensive effect when given with amlodipine. Plasma concentration of sildenafil increased by cimetidine.