Effect of food on nifedipine pharmacokinetics

The effect of food on the bioavailability of nifedipine (Procardia), 10 mg capsules, was studied. Each of 15 male volunteers received a single oral 10 mg dose with 120 ml water under three conditions: fasting, after a low-fat (high-carbohydrate) meal, and after a high-fat meal. An open, three-way Latin-square design was employed with a 4-day washout period between administrations. Serial blood samples were collected just before the dose (0 hour) and from 0 to 8 hours after administration. Nifedipine assays were performed by GLC/electron capture detection. Diet did not appreciably alter the AUC from 0 to 8 hours, the AUC from 0 to infinity, or the elimination half-life. The time to peak (tmax) and peak concentrations (Cmax) were significantly altered by food. The mean Cmax values for fasting, low-fat, and high-fat meals were 78.9, 42.2, and 58.7 ng/ml, respectively. The mean tmax values for these three conditions were 0.97, 1.89, and 1.07 hours, respectively. The results indicate that food, in particular a low-fat (high-carbohydrate) meal, slows the rate but does not alter the extent of nifedipine absorption. Insofar as certain side effects (e.g., flushing and headache) may be related to the high peak plasma levels associated with rapid absorption, administration with meals might serve to reduce the incidence of such effects. Clinical trials would be necessary to confirm this possibility. For the majority of patients on routine maintenance therapeutic regimens, nifedipine capsules may be administered without regard to food intake.