# A randomised trial of ondansetron for the treatment of irritable bowel syndrome with diarrhoea



## Jeffrey Roberts

*A randomised trial of ondansetron for the treatment of irritable bowel syndrome with diarrhoea*

Gut doi:10.1136/gutjnl-2013-305989


Klara Garsed1, 
Julia Chernova1, 
Margaret Hastings2, 
Ching Lam1, 
Luca Marciani3,
Gulzar Singh1, 
Amanda Henry4, 
Ian Hall4, 
Peter Whorwell2, 
Robin Spiller1

+Author Affiliations


1Nottingham Digestive Diseases Biomedical Research Unit, Queens Medical Centre, Nottingham, UK
2Neurogastroenterology Unit, Wythenshawe Hospital, Manchester, UK
3Sir Peter Mansfield Magnetic Resonance Imaging Centre, University of Nottingham, Nottingham, UK
4Department of Molecular Medicine, School of Surgical and Medical Sciences, University of Nottingham, Nottingham, UK

Correspondence toProfessor Robin Spiller, Nottingham Digestive Diseases Centre, University Hospital, Nottingham NG7 2UH, UK; [email protected]

Received 30 August 2013
Revised 31 October 2013
Accepted 17 November 2013
Published Online First 12 December 2013
Abstract

Background Irritable bowel syndrome with diarrhoea (IBS-D) is particularly debilitating due to urgency and episodic incontinence. Some 5-hydroxytryptamine 3 (5-HT3) receptor antagonists (5-HT3RAs) have proven effective but have serious side effects. Ondansetron, also a 5-HT3RA, has been widely used as an antiemetic with an excellent safety record for over two decades. Our aim was to assess its effectiveness in IBS-D.

Methods 120 patients meeting Rome III criteria for IBS-D entered a randomised, double-blind, placebo-controlled crossover study of 5 weeks of ondansetron 4 mg versus placebo with dose titration allowed, up to two tablets three times daily in the first 3 weeks. Patients completed daily diaries documenting stool consistency using the Bristol Stool Form score. Gut transit was measured in the last week of each treatment. The primary endpoint was average stool consistency in the last 2 weeks of treatment.

Results Ondansetron significantly improved stool consistency (mean difference in stool form between ondansetron and placebo −0.9, 95% CI −1.1 to −0.6, p<0.001). Compared with placebo, patients on ondansetron experienced fewer days with urgency (p<0.001), lower urgency scores (p<0.001), reduced frequency of defaecation (p=0.002) and less bloating (p=0.002), although pain scores did not change significantly. IBS symptom severity score fell more with ondansetron than placebo (83±9.8 vs 37±9.7, p=0.001). 65% reported adequate relief with ondansetron but not placebo compared with 14% reporting relief with placebo but not ondansetron, relative risk 4.7, 95% CI 2.6 to 8.5, p<0.001.

Conclusions Ondansetron relieves some of the most intrusive symptoms of IBS-D, namely loose stools, frequency and urgency.

Significance of this study

What is already known about this subject?



5-Hydroxytryptamine 3 receptor antagonists (5-HT3RAs) improve symptoms of irritable bowel syndrome with diarrhoea (IBS-D).



Alosetron, the best studied 5-HT3RA, was withdrawn from general use because of constipation and rarely ischaemic colitis.



Ondansetron is a 5-HT3RA widely used as an anti-nauseant for over 20 years and never associated with ischaemic colitis.


What are the new findings?



Ondansetron improves symptoms of frequent loose stools with urgency characteristic of IBS-D.



Ondansetron slows the accelerated colonic transit associated with IBS-D.



Those with severe diarrhoea respond less well.


How might it impact on clinical practice in the foreseeable future



Ondansetron is a safe inexpensive 5-HT3RA available worldwide which could improve symptoms in many patients with IBS-D with mild to moderate symptoms.



The main benefit, which is seen within 7 days, is to reduce urgency.



The median dose is 4 mg per day in those who respond.


Complete Full Text is Here >>

Copyright © 2014 BMJ Publishing Group Ltd & British Society of Gastroenterology.


----------



## Queensgirl52

My husband was given 8 mg ondansetron tablets when he went through six months of chemotherapy last year. He never needed them, so they're all here and I'd like to give them a try. Do you recommend that I cut the pills in half?


----------



## Jeffrey Roberts

I *strongly* recommend that you speak to your doctor first as there are several contraindications for taking this medication. It may not be right for you.

Jeff


----------



## PD85

Queensgirl52 said:


> My husband was given 8 mg ondansetron tablets when he went through six months of chemotherapy last year. He never needed them, so they're all here and I'd like to give them a try. Do you recommend that I cut the pills in half?





Jeffrey Roberts said:


> I *strongly* recommend that you speak to your doctor first as there are several contraindications for taking this medication. It may not be right for you.
> 
> Jeff


Please work with your doctor through the process, but if I were in your situation I would try them for sure.


----------



## jmc09

I was on one of these trials and Ondansetron did very little for me at all.

The big problem with Ondansetron is its one of the weakest of the HT3 -setron drugs and its effects are much weaker than the big hitters such as Alosetron and Ramosetron.

It really gets me down that the people who are in charge of licencing these drugs are just pussyfooting around and simply dont understand the misery us sufferers go through every day of our lives.


----------



## NHow

It's working for me after just over two months. However I need to take the syrup so I can use a lower dose that the tablets. You shouldn't cut the tablets in half

because they have enteric coating. Definitely go speak with your doctor. Good luck.


----------

