Effect of anti-obesity drugs promoting energy expenditure, yohimbine and ephedrine, on gastric emptying in obese patients.

Author: Jonderko K, Kucio C

Author affiliation: Department of Gastroenterology, Silesian School of Medicine, Katowice, Poland.

Publication date & source: 1991.08, Aliment Pharmacol Ther., 5(4):413-8.

Publication type: Clinical Trial; Randomized Controlled Trial

The effect of ephedrine, a non-selective adrenoreceptor agonist, and yohimbine, a selective alpha 2-adrenolytic drug, on gastric emptying of a radiolabelled solid meal was examined in groups of 8 (all women) and 15 (4 men and 11 women) obese patients, respectively. Patients were given orally, double-blind in random order, placebo or 50 mg ephedrine in the first group, and placebo or 15 mg yohimbine in the second group, 1.5 h prior to the gastric emptying measurement performed with the use of a gamma camera. Yohimbine did not significantly affect gastric emptying--the fraction of the meal retained within the stomach at the end of the examination (that is after 90 min), F90, amounted to 71.0 +/- 3.8% (placebo) and 66.8 +/- 4.1% (yohimbine); the gastric emptying index, Ix, was 0.737 +/- 0.106 min-1 x 10(-2) (placebo) and 0.885 +/- 0.128 min-1 x 10(-2) (yohimbine). A significant delay in gastric emptying was observed after administration of ephedrine: F90 increased from 70.3 +/- 5.1% after placebo to 80.9 +/- 3.0% after ephedrine, P less than 0.02, and Ix decreased from 0.747 +/- 0.142 min-1 x 10(-2) to 0.461 +/- 0.080 min-1 x 10(-2) after ephedrine, P less than 0.02. We conclude that the inhibitory influence of ephedrine on gastric emptying, and thus possibly on satiety, makes it a candidate for trial as pharmacological support of a low-energy diet treatment of obesity.