Table 2.
Characteristics of randomized controlled trials of selective serotonin-reuptake inhibitors 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 |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Fluoxetine vs placebo | |||||||||||
| Kuiken et al35 | 20 mg qhs | 6 wk | 40 | Adults with IBS (Rome I) | 0 | 0 | 0 | NA/NR | NA/NR | 0 | 0 for flatulence 0 for incomplete evacuation |
|
| |||||||||||
| Paroxetine vs placebo | |||||||||||
| Tabas et al36 | HFD ± 10 mg qd; titration at wk 4, 8, and 11 prn; 40 mg qd maximum dose | 12 wk | 81 | Adults with IBS (Rome I) | 0 | 0 | ++* | NA/NR | NA/NR | NA/NR | + improvement in stool passage |
| Masand et al37 | 12.5 mg qd of the controlled release form; titrated biweekly to response and tolerability; 50 mg qd maximum dose | 12 wk | 72 | Adults with IBS (Rome II) | 0 | 0 | ++ | NA/NR | NA/NR | NA/NR | ++ for CGI-severity improvement 0 for constipation, diarrhea, and distress |
|
| |||||||||||
| Citalopram vs placebo | |||||||||||
| Tack et al38 | 20 mg qd for first 3 wk then 40 mg qd for wk 4–6 | 6 wk | 23 | Adults with IBS (Rome II) | + for number of days per wk with abdominal pain | + | NA/NR | NA/NR | NA/NR | NA/NR | + for number of days with loose stools, straining, and incomplete evacuation |
| Talley et al33 | 40 mg qd† | 12 wk | 33 | Adults with IBS (Rome II) | 0 | NA/NR | 0 for adequate IBS symptom relief at last wk, adequate relief for ≥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 |
Notes:
Endpoint measured was “improvement in overall well-being”.
Treatment in this study included an imipramine 25–50 mg/d arm as well; only the citalopram 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; HFD, high fiber diet; IBS, irritable bowel syndrome; NA/NR, not assessed or not reported; SF-36, Medical Outcomes Study Short Form.