CYP3A4 and Hypertension: Table 2 lists common foods and herbals used in the general population that have been shown to inhibit or induce CYP3A4 activity or expression [73,74,75,76,77,78,79,80,81,82,83,84,85,86,87,88,89,90,91,92]. The best-known example is grapefruit-drug interactions that causes marked and variable increases in plasma concentration up to 250% of various orally administered CYP3A4 substrate drugs, including felodipine and nifedipine for treating hypertension, midazolam for anesthesia and cyclosporin for immunosuppression [74,98,99,100,101].