<p>Increased plasma cone with strong CYP3A4 inhibitors (eg ketoconazole, ritonavir, itraconazole, erythromycin, clarithromycin, grapefruit juice). Decreased plasma cone with strong CYP3A4 inducers [eg rifampin, dexamethasone, phenytoin, carbamazepine, phenobarb, St. John&#39;s wort (Hypericum perforatum)]. Anticoagulants eg warfarin, acenocoumarol (periodically monitor platelets, prothrombin time/INR &amp; physical exam).</p>