Impairment of captopril bioavailability by concomitant food and antacid intake.
Single oral doses of captopril (50 mg) were given in a randomized cross-over study to 10 healthy volunteers after fasting, after a standardized breakfast (440 kcal; 1804 kJ) or with 50 ml of an antacid suspension. Blood and urine samples were analyzed by gas chromatography. The peak captopril concentrations attained were 701 +/- 81 ng/ml (mean +/- s.e.m.) after fasting, 351 +/- 56 ng/ml with an antacid (p less than 0.05) and 140 +/- 14 ng/ml after a meal (p less than 0.01). The peak concentrations were reached in 0.5, 0.9 and 1.5 h (p less than 0.01), and the areas under the blood concentration-time curves were 782 +/- 86, 456 +/- 60 (p less than 0.05) and 344 +/- 47 ng X h/ml (p less than 0.01), respectively. The relative bioavailability of captopril was 0.66 and 0.48 with antacid and after food, respectively. The deleterious effect of food - but not that of antacid - was reflected as a delayed hypotensive activity of captopril.
D000328:Adult; D000863:Antacids / Q000494:pharmacology*; D001682:Biological Availability; D001794:Blood Pressure / Q000187:drug effects; D002216:Captopril / Q000097:blood / Q000378:metabolism* / Q000652:urine; D004311:Double-Blind Method; D004347:Drug Interactions; D005260:Female; D005502:Food; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D007700:Kinetics; D008297:Male; D011392:Proline / Q000031:analogs & derivatives*; D011897:Random Allocation
D000863:Antacids; D011392:Proline; D002216:Captopril