Felodipin-Natrapharm Drug Interactions

The blood pressure-lowering effect of felodipine may be increased by other blood pressure-lowering drugs and by certain (tricyclic) antidepressants. The breakdown of felodipine involves a certain enzyme system in the liver (cytochrome P450 3A4). Concurrently, administered drugs interfere with this enzyme system may therefore, interact with felodipine to produce increased blood levels of felodipine when medicinal products that contain such drugs as cimetidine, erythromycin, itraconazole or ketoconazole are used at the same time. Grapefruit, which contains enzyme-inhibiting flavonoids, can also increase the plasma level of felodipine; reduced blood levels of felodipine when medicinal products that contain such drugs as carbamazepine, phenytoin or barbiturates are used at the same time. Please bear in mind that these precautions may also apply to recently used medicines.