Randomized double-blind crossover study to determine the effects of erythromycin on small intestinal nutrient absorption and transit in the critically ill.

BACKGROUND: The gastrokinetic drug erythromycin is commonly administered to critically ill patients during intragastric feeding to augment small intestinal nutrient delivery. However, erythromycin has been reported to increase the prevalence of diarrhea, which may reflect reduced absorption and/or accelerated small intestinal transit. OBJECTIVE: The objective was to evaluate the effects of intravenous erythromycin on small intestinal nutrient absorption and transit in the critically ill. DESIGN: On consecutive days, erythromycin (200 mg in 20 mL 0.9% saline) or placebo (20 mL 0.9% saline) were infused intravenously between -20 and 0 min in a randomized, blinded, crossover fashion. Between 0 and 30 min, a liquid nutrient containing 3-O-methylglucose (3-OMG), [13C]triolein, and [(99m)Tc]sulfur colloid was administered directly into the small intestine at 2 kcal/min. Serum 3-OMG concentrations and exhaled (13)CO2 (indices of glucose and lipid absorption, respectively) were measured. Cecal arrival of the infused nutrient was determined by scintigraphy. Data are medians (ranges) and were analyzed by using Wilcoxon's signed-rank test. RESULTS: Thirty-two mechanically ventilated patients were studied. Erythromycin increased small intestinal glucose absorption [3-OMG AUC360: 105.2 (28.9-157.0) for erythromycin compared with 91.8 (51.4-147.9) mmol/L · min for placebo; P = 0.029] but tended to reduce lipid absorption [cumulative percentage dose (13)CO2 recovered: 10.4 (0-90.6) compared with 22.6 (0-100) %; P = 0.06]. A trend to slower transit was observed after erythromycin [300 (39-360) compared with 228 (33-360) min; P = 0.07]. CONCLUSIONS: Acute administration of erythromycin increases small intestinal glucose absorption in the critically ill, but there was a tendency for the drug to reduce small intestinal lipid absorption and slow transit. These observations have implications for the use of erythromycin as a gastrokinetic drug in the critically ill. This trial was registered in the Australian New Zealand Clinical Trials Registry as ACTRN 12610000615088.

Effects of a protein preload on gastric emptying, glycemia, and gut hormones after a carbohydrate meal in diet-controlled type 2 diabetes.

OBJECTIVE: We evaluated whether a whey preload could slow gastric emptying, stimulate incretin hormones, and attenuate postprandial glycemia in type 2 diabetes. RESEARCH DESIGN AND METHODS: Eight type 2 diabetic patients ingested 350 ml beef soup 30 min before a potato meal; 55 g whey was added to either the soup (whey preload) or potato (whey in meal) or no whey was given. RESULTS: Gastric emptying was slowest after the whey preload (P < 0.0005). The incremental area under the blood glucose curve was less after the whey preload and whey in meal than after no whey (P < 0.005). Plasma glucose-dependent insulinotropic polypeptide, insulin, and cholecystokinin concentrations were higher on both whey days than after no whey, whereas glucagon-like peptide 1 was greatest after the whey preload (P < 0.05). CONCLUSIONS: Whey protein consumed before a carbohydrate meal can stimulate insulin and incretin hormone secretion and slow gastric emptying, leading to marked reduction in postprandial glycemia in type 2 diabetes.

Effects of Iberogast on proximal gastric volume, antropyloroduodenal motility and gastric emptying in healthy men.

OBJECTIVE: The herbal preparation Iberogast has been reported to improve upper abdominal symptoms in functional dyspepsia (FD) and to decrease fundic tone, increase antral contractility, and decrease afferent nerve sensitivity in experimental animals. The effects of Iberogast on the human gastrointestinal tract have not been evaluated. METHODS: We investigated the effects of oral control and Iberogast, each administered as a single dose (1.1 mL), in a double-blind randomized fashion, on proximal gastric volume (part A), antropyloroduodenal motility (part B), and gastric emptying and intragastric distribution of a solid/liquid meal (part C) for 120 minutes, in nine (part A), 12 (part B), and eight (part C) healthy men. RESULTS: Iberogast increased proximal gastric volume (max volume; control 104+/-12 mL, Iberogast 174+/-23 mL, P<0.05) (part A), increased the motility index of antral pressure waves in the first 60 minutes (P<0.05) without affecting pyloric or duodenal pressures (part B), and slightly increased the retention of liquid in the total stomach between 10 and 50 minutes (P<0.01), but had no effect on gastric emptying of solids or intragastric distribution (part C). CONCLUSIONS: Iberogast affects gastric motility in humans, probably in a region-dependent manner. The stimulation of gastric relaxation and antral motility may contribute to the reported therapeutic efficacy of Iberogast in FD.