5. Chronic concomitant treatment with strong CYP3A4 inhibitors (eg, phenytoin, carbamazepine, rifampin, rifabutin, rifapentine, phenobarbital, and St. John's Wort) should be avoided because it may significantly decrease cabozantinib concentrations. If patients are taking any strong CYP3A4 inhibitors, alternate medications with no or minimal CYP3A4 inhibitors should be sought prior to trial enrollment.