Two very small double-blind placebo controlled RCTs «Sharbafchi MR, Afshar Zanjani H, Saneian Z, et al....»1, «Sharbafchi MR, Afshar H, Adhamian P, et al. Effect...»2 measured the effect of SNRI drugs on pain and other irritable bowel syndrome symptoms. Both studies suggested some benefit from the treatment, but magnitude of effect is not possible to assess due to substantial imprecision.
The evidence certainty was downgraded due to risk of bias and imprecision. Both studies were from the same center in Iran, which may decrease the applicability of results in Finnish context.
| Reference | Study type | Population | Intervention and comparison | Outcomes | Risk of bias |
|---|---|---|---|---|---|
| RCT=randomized controlled trial; SR=systematic review; MA=meta-analysis; IBSSS= Irritable Bowel Syndrome Severity Scoring System | |||||
| «Sharbafchi MR, Afshar Zanjani H, Saneian Z, et al....»1 | RCT | Patients with moderate‑to‑severe IBS, ROME III criterion. Iranian study. |
Duloxetine started 30-60 mg/day vs Placebo |
IBSSS | High |
| «Sharbafchi MR, Afshar H, Adhamian P, et al. Effect...»2 | RCT | Patients with moderate‑to‑severe IBS, ROME III criterion. Iranian study. |
Venlafaxine 150mg/day for 3 months vs placebo | Gastrointestinal symptom questionnaire, IBSSS | High |
| Reference | Comments |
|---|---|
| «Sharbafchi MR, Afshar Zanjani H, Saneian Z, et al....»1 | Exclusion criteria: organic disease, psychiatric disease. Patients from a psychosomatic clinic. A study conducted in Iran. Duloxetine started 30 mg/day, after 4-7 days raised to 60mg/day. No primary outcome defined, very small sample size, no power calculation, drop outs (3/40) excluded from analysis, allocation concealment unclear. IBSSS: pain, defecation disorder, bloating, effect of disease on daily activities, extraintestinal symptoms, each VAS 0-10, total score 500. |
| «Sharbafchi MR, Afshar H, Adhamian P, et al. Effect...»2 | Exclusion criteria: EX: other disease, psychiatric disease, antidepressant or anti-anxiolytic
medication within 2 wks prior. Patients from psychosomatic clinic. A study conducted in Iran. Venlafaxine started 37,5 mg for 2 wks, then75mg/day 2 wks, 150mg/day. No primary outcome defined, very small sample size, no power calculation (a pilot study), dropouts (4/34) excluded from analysis. Gastrointestinal symptom questionnaire: frequency of abdominal pain/discomfort, abdominal pain improvement after defecation, and association of frequency defecations with abdominal pain, an association of loose/hard stool with abdominal pain and frequency of having loose/hard stool during the past 3 past months, scoring 0-5/each symptom IBSSS: pain, defecation disorder, bloating, effect of disease on daily activities, extraintestinal symptoms, each VAS 0-10, total score 500 |
Results
| Reference | Number of studies and number of patients (I/C) | Follow-up time | Mean (sd) I | Mean (sd) C | Relative effect (95% CI) |
|---|---|---|---|---|---|
| Level of evidence: very low The quality of evidence is downgraded due to study limitations and imprecision (two levels). I=intervention; C=comparison; CI=confidence interval |
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| «Sharbafchi MR, Afshar Zanjani H, Saneian Z, et al....»1 | 18/19 | 12 wks | 177 (44) | 204 (56) | - |
| Reference | Number of studies and number of patients (I/C) | Follow-up time | Mean (sd) I | Mean (sd) C | Relative effect (95% CI) |
|---|---|---|---|---|---|
| Level of evidence: very low The quality of evidence is downgraded due to study limitations and imprecision (two levels). I=intervention; C=comparison; CI=confidence interval |
|||||
| «Sharbafchi MR, Afshar H, Adhamian P, et al. Effect...»2 | 16/14 | 12 wks | 3,87±0,96 | 4,93±1.54 | - |