Gender-related differences in slowing colonic transit by a 5-HT3 antagonist in subjects with diarrhea-predominant irritable bowel syndrome.
OBJECTIVE
To evaluate the influence of gender on the effect of a 5-HT3 antagonist, alosetron, 1 mg b.i.d., on GI and colonic transit in D-IBS.


METHODS
Thirty patients (15 male, 15 female) with D-IBS received 1 mg b.i.d. alosetron for 6 wk. Transit was measured by scintigraphy at baseline and at the end of treatment.


RESULTS
Alosetron, 1 mg b.i.d., significantly retarded small bowel and, proximal and overall colonic transit in the 30 patients with D-IBS. The effect of alosetron on the primary endpoint, colonic geometric center at 24 h, was significantly greater in females than in males (p < 0.05). However, two females showed no slowing of colonic transit on treatment. Among male patients, two of 15 had a slowing of colonic transit at 24 h that was greater than the mean change in female patients, suggesting responsiveness to alosetron among a subgroup of males.


CONCLUSIONS
A 5-HT3 antagonist, alosetron, significantly retards small intestinal and colonic transit in diarrhea-predominant IBS patients, with significantly greater female to male responsiveness. Gender partly contributes to differences in the serotonergic control of intestinal and colonic transit in patients with D-IBS.
Viramontes
B E
BE
Enteric Neuroscience Program, Gastroenterology Research Unit, Mayo Clinic and Mayo Foundation, Rochester, Minnesota 55905, USA.
Camilleri
M
M
McKinzie
S
S
Pardi
D S
DS
Burton
D
D
Thomforde
G M
GM
D000328:Adult; D002243:Carbolines / Q000494:pharmacology*; D003106:Colon / Q000187:drug effects* / Q000503:physiopathology*; D003109:Colonic Diseases, Functional / Q000150:complications / Q000503:physiopathology*; D003967:Diarrhea / Q000150:complications / Q000503:physiopathology*; D005260:Female; D005772:Gastrointestinal Transit / Q000187:drug effects*; D006801:Humans; D008297:Male; D012702:Serotonin Antagonists / Q000494:pharmacology*; D012737:Sex Factors; D013997:Time Factors
D002243:Carbolines; D012702:Serotonin Antagonists; C090840:alosetron