<p>May interact with Nitrates for example, Isosorbide, Nitroglycerin, Alpha adrenergic blockers, Antihypertensives, Alcohol, Antacids (magnesuim hydroxide/aluminum hydroxide), Ketoconazole, Ritonavir, Erythromycin, Itraconazole, Grapefruit juice, other HIV protease inhibitors, Rifampin, Carbamazepine, Phenytoin &amp; Phenobarbital.</p>