Non-absorbable antibiotics for managing intestinal gas production and gas-related symptoms

Background: Simethicone, activated charcoal and antimicrobial drugs have been used to treat gas-related symptoms with conflicting results. Aim: To study the relationship between gaseous symptoms and colonic gas production and to test the efficacy of rifaximin, a new non-absorbable antimicrobial agent, on these symptoms. Methods: Intestinal gas production was measured by. hydrogen (H-2) and methane (CH4) breath testing after lactulose in 21 healthy Volunteers and 34 functional patients. Only the 34 functional, patients took part in a double-blind, double-dummy controlled trial, receiving, at random, rifaximin (400 mg b.d per 7 days), or activated charcoal (400 mg b.d per 7 days). The following parameters were evaluated at the start of the study and 1 and 10 days after therapy: bloating, abdominal pain, number of flatus episodes, abdominal girth, and cumulative breath H-2 excretion. Results: Hydrogen excretion was greater in functional patients than in healthy volunteers. Rifaximin, but not activated charcoal, led to a significant reduction in H-2 excretion and overall severity of symptoms. In particular, in patients treated with rifaximin, a significant reduction in the mean number of natus episodes and of mean abdominal girth was evident. Conclusions: In patients with gas-related symptoms the colonic production of H-2 is increased. Rifaximin significantly reduces this production and the excessive number of flatus episodes.