Impairment of captopril bioavailability by concomitant food and antacid intake

Int J Clin Pharmacol Ther Toxicol. 1984 Nov;22(11):626-9.

Abstract

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.

MeSH terms

  • Adult
  • Antacids / pharmacology*
  • Biological Availability
  • Blood Pressure / drug effects
  • Captopril / blood
  • Captopril / metabolism*
  • Captopril / urine
  • Double-Blind Method
  • Drug Interactions
  • Female
  • Food*
  • Heart Rate / drug effects
  • Humans
  • Kinetics
  • Male
  • Proline / analogs & derivatives*
  • Random Allocation

Substances

  • Antacids
  • Proline
  • Captopril