A randomized, placebo-controlled, crossover, double-blind trial of the NK1 receptor antagonist aprepitant on gastrointestinal motor function in healthy humans

Background Little is known about the role of tachykinins on human gastrointestinal motility and no data exist on the possible effect of an NK1 receptor antagonist. Aim To examine the effect of an antiemetic dose of the selective NK1 receptor antagonist aprepitant on gastrointestinal propulsion in healthy humans. Methods Twelve healthy volunteers participated in a crossover, double-blind study. In random order, each volunteer had a 125-mg capsule of aprepitant or placebo on day 1 followed by an 80-mg capsule of aprepitant or placebo on days 2-5. Gamma camera imaging was used to measure gastric emptying, small intestinal transit and colonic transit of a radiolabelled, 1600-kJ mixed liquid and solid meal ingested on day 2. Results Aprepitant did not change gastric retention at 15 min, gastric half emptying time, gastric mean transit time, time to small intestinal transit of 10%, small intestinal mean transit time or colonic geometric centre after 24, 48 and 72 h. Conclusions A 125-mg capsule of aprepitant followed by an 80-mg capsule of aprepitant each of the next 2-5 days did not induce major changes in the propulsive function of the gastrointestinal tract in the small number of healthy volunteers investigated.