GALLBLADDER FASTING VOLUME IS REDUCED AND GALLBLADDER POSTPRANDIAL EMPTYING IS ENHANCED BY INTRAVENOUS ERYTHROMYCIN

It has been recently shown that erythromycin, a macrolide antibiotic, exhibits prokinetic properties, by enhancing gastric emptying in healt h and disease and by inducing gallbladder contraction. The aim of the study was to further investigate the effect of intravenous erythromyci n on gallbladder motility during fasting and postprandial states. In 1 0 healthy male subjects gallbladder emptying was assessed by ultrasono graphy on three different occasions, each in a random sequence, as fol lows: (1) after giving 300 ml of fresh milk and infusing normal saline as placebo (postprandial emptying), (2) after infusing 200 rug of ery thromycin during the fasting state, and (3) after infusing 200 mg of e rythromycin along with ingestion of 300 mi of fresh milk. Infusion of erythromycin and placebo lasted 10 min. From the emptying curves, the duration of the lag phase of emptying, the ejection fraction of emptyi ng, and the time by which maximal emptying was achieved were calculate d. Infusion of erythromycin induced an immediate contraction [lag phas e (+/-SD): 1.3 +/- 2.6 SD min] of the gallbladder by 42.1 +/- 22% of i ts initial volume. Infusion of erythromycin during the postprandial st ate significantly decreased the duration of the lag phase (1.3 +/- 3.5 min after erythromycin plus test meal versus 3.6 +/- 4.2 min after te st meal only, P < 0.04) and significantly increased the ejection fract ion (78 +/- 8.5% after erythromycin plus test meal versus 60.6 +/- 8.5 % after test meal only, P < 0.0008). It is concluded that intravenousl y given erythromycin induces contraction of the gallbladder during the fasting state and enhances postprandial gallbladder emptying by accel erating the initiation and increasing the extent of emptying.