Influence of antacids on the bioavailability of glibenclamide.

A single oral dose of glibenclamide (2.5 mg) was given to eight healthy volunteers in a randomized cross-over study after a standardized fasting and breakfast (374 kcal), with or without a concomitant intake of 10 ml of antacid suspension. Serum glibenclamide levels were determined by means of a specific radioimmunoassay method. The areas under the blood concentration-time curves (AUC0-infinity), with or without antacid, were 408.17 +/- 168.25 and 307.9 +/- 84.13 ng/ml (p less than 0.05), respectively. The peak concentrations of 96.88 +/- 49.9 and 66.19 +/- 32.35 ng/ml/h (p less than 0.05) with or without antacid, were reached in 4.13 and 3.81 h, respectively. Values of tmax, Vd and t1/2 were not affected by the presence of the antacid. A 33% increase in bioavailability of glibenclamide emerged, as seen from the respective AUC values, but no clinically remarkable effect was observed in the subjects.