Introduction Antidepressants have a mild analgesic effect and are commonly used in the management of irritable bowel syndrome (IBS); however, the quality of the clinical evidence to support the use of tricyclic antidepressants (TCAs) and selective serotonin inhibitors (SSRIs) in IBS is unclear. The aim of this literature review was to systematically identify and analyse published evidence on the efficacy of TCAs and SSRIs for IBS.
Methods A systematic search of the medical literature was conducted using the PubMed, Embase, and Cochrane databases. Search terms included ‘irritable bowel syndrome’, ‘spastic colon’, ‘irritable colon’, ‘functional diseases, colon’ and a mixture of agent terms – including antidepressants, tricyclic, and SSRIs. Randomised placebo-controlled trials evaluating the efficacy of antidepressants (SSRIs and TCAs) in adult patients with IBS were eligible for inclusion. Exclusion criteria included absence of placebo arm, patients <18 years of age, and dual publication. Only antidepressants available in the UK were included in this analysis.
Results A total of 628 unique titles and abstracts were retrieved; 581 records were excluded upon title or abstract review and 33 upon full-text review. The final review included 14 studies: 7 reporting on TCAs, 6 on SSRIs, and 1 comparing both an SSRI and a TCA vs. placebo. Agents included in the analysis were citalopram, paroxetine, fluoxetine, imipramine, amitriptyline, trimipramine and doxepin. Overall, 797 patients were included in the 14 studies, with 240 receiving a TCA, 171 receiving an SSRI and 386 receiving placebo. Of the nine studies (475 patients) that reported IBS subtype, 50% of patients had diarrhoea-predominant IBS, 32% had constipation-predominant IBS (IBS-C) and 19% had alternating-type IBS. Treatment duration ranged from 4–12 weeks. The most common IBS-related outcome measures were for global symptom relief and improvements in abdominal pain/discomfort. Three studies reported on quality of life, while only limited data were available for treatment satisfaction. Most outcomes did not align well with those now required for FDA and EMA regulatory approval of medicines to treat IBS-C.
Conclusion The evidence base for the use of antidepressants in IBS is of low quality, making estimates of effect very uncertain. Data for the efficacy of antidepressants in IBS subtypes are especially limited. Further studies are required to support the off-label use of antidepressants in IBS.
Study funded by Almirall UK.
Disclosure of Interest M. Rance Employee of: Almirall UK, L. Lindner Employee of: Almirall S. A., A. C. Ford: None Declared.