Gallbladder contraction induced by intravenous erythromycin administration. Relation to body mass index.

BACKGROUND/AIMS: To study the action of intravenously administered erythromycin lactobionate on human gallbladder volume, as a possible preventive method against gallbladder stone formation, in high risk patients such as those in sepsis, long standing fasting periods or those receiving prolonged total parenteral nutrition or octreotide.

MATERIALS AND METHODS

Twenty-two volunteers randomized to receive intravenously either erythromycin lactobionate 7 mg per kg (study group) or normal saline (controls). We measured ultrasonographically the gallbladder volume before and at 5, 15, 35, 55, 90, 120 and 180 min after the infusion.

RESULTS

Erythromycin induced a biphasic gallbladder contraction, with maximum contractility at 15 min (10.2%) and between 120 and 180 min (22.6%), compared to normal saline controls. Late contractility was correlated to body mass index (BMI).

CONCLUSIONS

Erythromycin activity on gallbladder contraction is proved. Its biphasic action needs further investigation to find the involved mechanism(s). Long term administration is also necessary to test its efficacy in preventing gallbladder dilatation.