Influence of the pharmacological modification of gastric emptying on lactose digestion and gastrointestinal symptoms.

In lactose maldigesters the ingestion of food which retards gastric emptying improves tolerance to lactose. To study the effects of the pharmacological modification of gastric emptying on the speed of development of lactose-induced symptoms. After an overnight fast, 18 lactose maldigesters were given, in a randomized double-blind study design at 1-week intervals, either propantheline (as bromide 15 mg), metoclopramide (as hydrochloride 10 mg) or placebo, in identical capsules, 60 min before ingesting 50 g lactose coloured with 1 g carmine dye (to measure gastrointestinal transit time). Gastrointestinal symptoms, urinary galactose excretion, and breath hydrogen and blood glucose concentrations were recorded. The propantheline-induced prolongation of gastric emptying improved tolerance to lactose, as measured by reduced area under the gastrointestinal symptom score curve 0-12 h, compared to placebo (by 26%) (P < 0.05) or metoclopramide (by 30%) (P < 0.05). The total hydrogen excretion AUC (180 min follow-up) increased by 15% after metoclopramide as compared with placebo (P = 0.18). Propantheline decreased this variable by 15% from placebo (P = 0.17). No significant differences in blood glucose, urinary galactose or gastrointestinal transit time were found. In an oral lactose tolerance test, delaying gastric emptying with propantheline improved tolerance in lactose maldigesters, as measured by diminished gastrointestinal symptoms and reduced breath hydrogen concentration.