Objective: The aim of this study was to determine whether variations in the blood glucose concentration within the normal postprandial range affect the gastrokinetic action of erythromycin.
Methods: Six healthy male volunteers, aged 20-33 yr underwent measurements of gastric emptying on 2 separate days; blood glucose concentrations were maintained at approximately 4 mmol/L (72 mg/dl) on 1 day and at 8 mmol/L (144 mg/dl) on the other. The order of the two studies was randomized and they were separated by 4-7 days. On both days, erythromycin (3 mg/kg) was administered intravenously over 15 min immediately before consumption of 300 g minced beef labeled with 20 MBq 99mTc-sulphur colloid chicken liver and 150 ml water labeled with 67Ga-EDTA.
Results: Gastric emptying of solid (p < 0.05) and liquid (p < 0.0001) were slower at a blood glucose concentration of 8 mmol/L (144 mg/dl) when compared to 4 mmol/L (72 mg/dl). The slowing of gastric emptying was associated with greater retention of both solid and liquid in the proximal (p < 0.06) and distal (p < 0.01) stomach.
Conclusions: After administration of erythromycin, gastric emptying and intragastric distribution of solids and liquids is influenced by physiological changes in the blood glucose concentration.