Amitriptyline at low-dose and titrated for irritable bowel syndrome as second-line treatment (The ATLANTIS trial): protocol for a randomised double-blind placebo-controlled trial in primary care

Diagnosing and managing irritable bowel syndrome with predominant diarrhoea in clinical practice: online survey among gastroenterologists and general practitioners

Introduction

Irritable bowel syndrome (IBS) represents the most common disorder of gut-brain interaction encountered in clinical practice. The Rome IV criteria define the disorder. Over the years, many guidelines proposed guidance during the diagnostic and therapeutic approach of patients with presumed IBS.

Aim

This study investigates the management of IBS with predominant diarrhoea (IBS-D) by Belgian gastroenterologists (GE) and general practitioners (GP) in daily practice.

Methods

An online vignette-based survey was conducted exploring the diagnostic and therapeutic approach of patients suffering from IBS with predominant diarrhoea (IBS-D) in primary and secondary care.

Results

64 GE and 31 GP completed the survey. Abdominal pain and discomfort led to an IBS diagnosis in 88% and 84% of cases, respectively. The diagnosis rate dropped to 58.3% with diarrhoea as main presentation and 26.8% for patients aged 65. Additional tests were ordered by 89.5% of physicians, including biochemistry (77.9%), stool culture and parasites (59.3%), iFOBT (60.5%), breath testing (17.4%), imaging (12.8%), and endoscopy (9.3%). Upon normal results, 57% of physicians did not order further investigations. Both GP and GE preferred spasmolytics (64.3%) and dietary interventions (23.9%) as first-line treatment for IBS. Second-line treatment options included referral to a specialist or colleague (19.4%), dietary intervention (22.6%), neuromodulators (19.4%), and spasmolytics (14.5%). No GP initiated neuromodulators.

Conclusion

In Belgium, abdominal pain or discomfort are equivalent cardinal symptoms when diagnosing IBS. During the further diagnostic and therapeutic approach most physicians order only limited additional non-invasive testing. Spasmolytics and dietary interventions are favoured in first-line. Upon failure, only GE prescribe neuromodulators, while GP opt for referral. These findings are consistent with the general principles and recommendations outlined in the recently published Belgian guideline for IBS.

Comparing the efficacy of duloxetine and nortriptyline in alleviating the symptoms of functional dyspepsia - a randomized clinical trial

Aim

To compare the efficacy of Duloxetine and Nortriptyline in alleviating the symptoms of severity, anxiety, depression and quality of life in patients with functional dyspepsia (FD).

Material and method

We conducted a single-blinded 3-month trial of Duloxetine 20-30 mg daily in 20 patients and Nortriptyline 25 mg daily in 25 FD patients. The primary outcome measure was the severity of FD symptoms by Gastrointestinal symptoms rating scale. Secondary measures included Hamilton Anxiety Rating Scale, Hamilton Depression Rating Scale, and Nepean Dyspepsia Index. the patients were measured in 3 stages.

Results

45 patients with FD with a mean age of 37.18 ± 10.62 years participated in the study. The severity of symptoms was significantly lower in the Nortriptyline group than in the Duloxetine group after three months (p = 0.031). The level of anxiety (p = 0.049), depression (p = 0.045) and quality of life (p = 0.046) improved significantly after three months in the Duloxetine group compared to Nortriptyline. Mediation analysis using linear regression revealed a significant mediator role for anxiety. This mediation analysis revealed a 21.13% reduction in anxiety in the Duloxetine group.

Conclusion

While both medications demonstrated efficacy, Nortriptyline appeared to be superior in symptom reduction. Duloxetine exhibited more advantages compared to Nortriptyline in addressing anxiety and depression and enhancing the overall quality of life. Also, Duloxetine may have a noteworthy impact, contributing to a 20% reduction in FD symptoms by lowering anxiety levels.

Clinical trial registration

https://en.irct.ir/trial/65512.

Amitriptyline at Low-Dose and Titrated for Irritable Bowel Syndrome as Second-Line Treatment in primary care (ATLANTIS): a randomised, double-blind, placebo-controlled, phase 3 trial

BACKGROUND

Most patients with irritable bowel syndrome (IBS) are managed in primary care. When first-line therapies for IBS are ineffective, the UK National Institute for Health and Care Excellence guideline suggests considering low- dose tricyclic antidepressants as second-line treatment, but their effectiveness in primary care is unknown, and they are infrequently prescribed in this setting.

METHODS

This randomised, double-blind, placebo-controlled trial (Amitriptyline at Low-Dose and Titrated for Irritable Bowel Syndrome as Second-Line Treatment [ATLANTIS]) was conducted at 55 general practices in England. Eligible participants were aged 18 years or older, with Rome IV IBS of any subtype, and ongoing symptoms (IBS Severity Scoring System [IBS-SSS] score ≥75 points) despite dietary changes and first-line therapies, a normal full blood count and C-reactive protein, negative coeliac serology, and no evidence of suicidal ideation. Participants were randomly assigned (1:1) to low-dose oral amitriptyline (10 mg once daily) or placebo for 6 months, with dose titration over 3 weeks (up to 30 mg once daily), according to symptoms and tolerability. Participants, their general practitioners, investigators, and the analysis team were all masked to allocation throughout the trial. The primary outcome was the IBS-SSS score at 6 months. Effectiveness analyses were according to intention-to-treat; safety analyses were on all participants who took at least one dose of the trial medication. This trial is registered with the ISRCTN Registry (ISRCTN48075063) and is closed to new participants.

FINDINGS

Between Oct 18, 2019, and April 11, 2022, 463 participants (mean age 48·5 years [SD 16·1], 315 [68%] female to 148 [32%] male) were randomly allocated to receive low-dose amitriptyline (232) or placebo (231). Intention-to-treat analysis of the primary outcome showed a significant difference in favour of low-dose amitriptyline in IBS-SSS score between groups at 6 months (-27·0, 95% CI -46·9 to -7·10; p=0·0079). 46 (20%) participants discontinued low-dose amitriptyline (30 [13%] due to adverse events), and 59 (26%) discontinued placebo (20 [9%] due to adverse events) before 6 months. There were five serious adverse reactions (two in the amitriptyline group and three in the placebo group), and five serious adverse events unrelated to trial medication.

INTERPRETATION

To our knowledge, this is the largest trial of a tricyclic antidepressant in IBS ever conducted. Titrated low-dose amitriptyline was superior to placebo as a second-line treatment for IBS in primary care across multiple outcomes, and was safe and well tolerated. General practitioners should offer low-dose amitriptyline to patients with IBS whose symptoms do not improve with first-line therapies, with appropriate support to guide patient-led dose titration, such as the self-titration document developed for this trial.

FUNDING

National Institute for Health and Care Research Health Technology Assessment Programme (grant reference 16/162/01).