Cheap prescription drug shown to help relieve IBS symptoms

A widely available prescription drug improves symptoms of irritable bowel syndrome (IBS), according to a new study.

IBS affects around 1 in 20 people worldwide. It causes abdominal pain and changes to bowel movements. The long-term condition, which has no known cure, fluctuates in severity over time.

It can have a substantial impact on quality of life and ability to work and socialise. Most treatments only have a modest effect, and people often have ongoing symptoms.

Now amitriptyline, commonly given at low doses for a range of health concerns, has been found to improve IBS symptoms.

Improvement almost twice as likely

The results come from the ATLANTIS trial, led by researchers at the Universities of Southampton, Leeds and Bristol. It was funded by the National Institute for Health and Care Research (NIHR).

Amitriptyline is commonly given at low doses for a range of health concerns, including back pain and migraines. NICE guidelines currently state that GPs could consider using amitriptyline at a low dose for IBS but, until now, the evidence for a benefit has been uncertain.

In the trial, GPs prescribed the drug to their patients. The patients managed their own dose based on the severity of their symptoms, using an adjustment document designed for the trial.

Most people with IBS are seen and managed in primary care by their GP. This means that the results of this trial are likely to be applicable to many people with the condition.

The results have been published in The Lancet. Patients taking amitriptyline were almost twice as likely to report an overall improvement in symptoms as those taking a placebo.

Good evidence of benefit

Now the trial team is recommending GPs support patients with IBS to use amitriptyline to manage their symptoms. They have made the dose adjustment document available for clinicians and patients.

Hazel Everitt, Professor of Primary Care Research at the University of Southampton, was Co-chief Investigator for the study.

She said: “Prior to ATLANTIS, GPs haven’t often prescribed amitriptyline for IBS as the research evidence was uncertain. Our new research provides good evidence of benefit.”

“GPs already prescribe low-dose amitriptyline for other conditions, such as chronic pain and poor sleep. When we interviewed GPs as part of this research, they were willing to prescribe it for IBS if the research evidence supported this.

“Participants were also keen to have another option to try to help their IBS symptoms. Most were happy to self-adjust their dose depending on symptoms and side effects.’’

Largest trial of amitriptyline for IBS

The ATLANTIS trial is the first randomised controlled trial of low-dose amitriptyline versus a placebo for IBS in primary care. It is also the largest trial of amitriptyline for IBS undertaken worldwide.

Overall, 463 people with IBS took part in the trial. They came from 55 GP surgeries across three UK regions – West Yorkshire, Wessex, and the West of England. Participants were randomly assigned to either receive amitriptyline or a placebo.

Participants controlled how many tablets of the trial medication they took. A patient dose adjustment document was developed with patient representatives. This helped them adjust the number of tablets they took, based on their symptoms and any side effects.

Effective treatment

Participants taking amitriptyline were almost twice as likely as those taking a placebo to report an overall improvement in IBS symptoms after six months.

Amitriptyline performed better across a wide range of IBS symptom measures. No safety concerns were identified and side effects in people on amitriptyline were mostly mild.

Alexander Ford, Professor of Gastroenterology at the University of Leeds, was the other Co-chief Investigator.

He said: “Amitriptyline is an effective treatment for IBS and is safe and well tolerated. This new, rigorously conducted research indicates that general practitioners should support patients in primary care to try low-dose amitriptyline if their IBS symptoms haven’t improved with recommended first-line treatments.”