Table 1.
Characteristics of randomized controlled trials of tricyclic antidepressants in irritable bowel syndrome ± diarrhea and efficacy outcomes
| Study | Treatment | Study duration | N | Population | Relief of abdominal pain | Relief of bloating | Global/overall IBS improvement | Stool frequency | Stool consistency | Urgency | Other efficacy assessments |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Amitriptyline vs placebo | |||||||||||
| Rajagopalan et al28 | 25–75 mg (titrated) | 12 wk | 40 | Adults with IBS (Rome criteria) | ++ | NA/NR | ++ | 0 | NA/NR | NA/NR | +++ for days felt well + for days with satisfactory bowel movements |
| Vahedi et al29 | 10 mg qhs | 2 mo | 50 | Adults with IBS-D (Rome II) | 0 | NA/NR | ++ for complete response | NA/NR | + | NA/NR | ++ for degree of symptom improvement 0 for passage of mucus + for feeling of incomplete defecation 0 for diarrhea |
|
| |||||||||||
| Desipramine vs placebo | |||||||||||
| Greenbaum et al30 | 50–150 mg qhs vs placebo | Three 6 wk periods | 41 | Adults with IBS* | NA/NR | 15/26 patients improved on desipramine | + | NA/NR | 0 for diarrhea | ||
| Overall completers | ++ | 0 | ++ for reduction in slow contractions | ||||||||
| I BS-D | + | 87% of patients who improved on desipramine had IBS-D | + | 0 | NA/NR | ++ for diarrhea + for slow contractions |
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| Drossman et al31 | 50–150 mg (titrated)† | 12 wk | 431 | Women with functional bowel disorder | 0 | NA/NR | 0 for responder analysis | + for post-treatment satisfaction | |||
| ++ for patients with detectable desipramine | NA/NR | NA/NR | NA/NR | 0 for IBS-QOL | |||||||
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| |||||||||||
| Imipramine vs placebo | |||||||||||
| Talley et al33 | 25–50 mg/d‡ | 12 wk | 34 | Adults with IBS (Rome II) | 0 | NA/NR | 0 for IBS symptom relief at last wk, for adequate relief at ≥50% of wk, and for CGI | NA/NR | NA/NR | NA/NR | 0 for anxiety and 0 for depression on HADS 0 for mental score and 0 for physical score on SF-36 |
| Abdul-Baki et al32 | 25 mg qhs | 12 wk | 107 | Women with IBS (Rome II) | NA/NR | NA/NR | 0 | NA/NR | NA/NR | NA/NR | 0 for QOL score on SF-36 |
Notes:
IBS defined as ≥3 months of abdominal pain or distress, occurring at least biweekly for which no organic cause is evident.
Study included 12-week treatment with cognitive behavioral therapy vs education and desipramine vs placebo comparisons; however, only desipramine vs placebo results are presented in this table.
Treatment in this study included a citalopram 20–40 mg/d arm as well; only the imipramine vs placebo results, including number of patients, are presented in this table.
Positive signs indicate significant improvement over placebo: + for P ≤ 0.05; ++ for P ≤ 0.01; +++ for P ≤ 0.001; ++++ for P ≤ 0.0001; 0 represents no statistically significant difference between active treatment and placebo.
Abbreviations: CGI, Clinical Global Impression scale; HADS, Hospital Anxiety and Depression Scale; IBS, irritable bowel syndrome; IBS-D, diarrhea-predominant IBS; IBS-QOL, Irritable Bowel Syndrome Quality of Life Questionnaire; NA/NR, not assessed or not reported; QOL, quality of life; SF-36, Medical Outcomes Study Short Form.