Induced hyperglycemia attenuates erythromycin-induced acceleration of hypertonic liquid-phase gastric emptying in type-I diabetic patients

Erythromycin has been found to be a gastrointestinal prokinetic agent of hy pertonic liquids, while acute hyperglycemia has been associated with delaye d gastric emptying in diabetic patients. Aim: To investigate whether hyperg lycemia, per se, reduces gastric motility during erythromycin-induced accel eration on gastric emptying of hypertonic liquids in diabetic patients. Met hods: In 12 type-I diabetic patients following a hypertonic radiolabeled li quid meal, gastric emptying was measured scintigraphically during normoglyc emia (5-8.9 mmol/l glucose) or hyperglycemia induced by intravenous (16-19 mmol/l) glucose infusion. The tests were performed on 4 separate days in ra ndom order after administering either placebo or 200 mg i.v. erythromycin. Results: In the hyperglycemic state compared to normoglycemia, the gastric emptying of the hypertonic liquid was reduced after placebo or erythromycin administration. The lag-phase duration (17.8+/-5.5 and 7.8+/-4.5 vs. 10.8/-3.4 and 3.7+/-2.5 min, respectively, p<0.001), the overall gastric emptyi ng time of the half meal (52.8+/-13 and 24.9+/-5.5 vs. 42.5+/-10.5 min and 16.6+/-6 min, respectively, p<0.001) and the retained percentage of liquid meal in the stomach at 60 and 100 min postprandially(p < 0.001) were signif icantly increased. Conclusions: The erythromycin-induced acceleration on ga stric emptying of hypertonic liquids in diabetic patients is related to the plasma glucose level. The induced hyperglycemia reduces the erythromycin-i nduced acceleration of liquid-phase gastric emptying, decreasing the overal l gastric emptying rate. In spite of the inhibitory effect of induced hyper glycemia on the gastric emptying of hypertonic liquids, erythromycin is sti ll able to accelerate the emptying rate and could prove to be a useful prok inetic agent under hyperglycemic conditions. Copyright (C) 2000 S. Karger A G, Basel.