Alosetron does not affect the visceral perception of gastric distension in healthy subjects.

Background: The effect of alosetron, a new specific 5-HT3 receptor antagonist, on the visceral perception in response to gastric distension was assessed in 12 healthy male subjects in a randomized, double-blind, placebo controlled crossover trial.

Methods: Each subject was given orally either alosetron 1 mg b.d. or placebo b.d. for 6 days (wash-out period 7-28 days). At the end of each dosing period, both isobarometric and isovolumetric gastric distensions were performed using an electronic barostat.

Results: Alosetron did not modify the gastric wall compliance (pressure-volume relationship). Alosetron had an effect similar to placebo on the visceral perception scores in both isobarometric and isovolumetric distensions. The mean (+/- SEM) thresholds for abdominal discomfort were, respectively, 16.8 +/- 0.7 mmHg and 825 +/- 61 mL with alosetron, 16.7 +/- 0.6 mmHg and 883 +/- 45 mL with Placebo (P = NS).

Conclusions: 5-HT3 receptors do not appear to be involved in the visceral perception of gastric distension in healthy subjects.