Contribution of individual differences in gastric emptying to variability in plasma propranolol concentrations

1 No correlation was found between the rate of gastric emptying and peak plasma propranolol concentrations in six hypertensive patients after single oral doses of 80 mg. 2 In four normal subjects given oral propranolol the peak plasma concentration was highest when a simultaneous injection of metoclopramide and lowest when propantheline was given. The mean time to peak was 1.5 h after metoclopramide, 2.8 h after normal saline and 4.5 h after propantheline. 3 Gastric emptying has some influence on the time of peak plasma propranolol concentrations but individual variation in its bioavailability is determined mainly by first-pass metabolism in the liver.