Therapeutic efficacy of duloxetine versus selective serotonin reuptake inhibitors in irritable bowel syndrome
IntroductionSelective serotonin reuptake inhibitors (SSRIs) are frequently used for irritable bowel syndrome, while duloxetine was evaluated in other similar psycho-somatic syndromes.ObjectiveThis prospective, single-blind trial intends to compare the efficacy of SSRIs and duloxetine in the treatment of irritable bowel syndrome.MethodsA group of 22 patients, 15 female and 7 male, mean age 50.2, diagnosed with irritable bowel syndrome according to the Rome II Diagnostic Criteria (1992) were treated with either an SSRI (escitalopram 20 mg/day, n = 6 or fluoxetine 40 mg/day, n = 6) or duloxetine (90 mg/day, n = 10). Patients were evaluated initially and every 4 weeks, for 6 months, using Hamilton Anxiety Rating Scale (HAMA), Hamilton Depression Rating Scale 17 items version (HAMD), Clinical Global Impressions -Severity/Improvement (CGI-I/S) and a 7-points Likert scale (LS) for self-evaluated severity.ResultsDuloxetine improved anxiety and depressive symptoms, as reflected by the significant decrease of HAMA (−17.6 points, p < 0.05) and HAMD scores (−18.2 points, p < 0.05) at week 12. SSRIs also reduced the affective symptoms, significantly to baseline (p < 0.05), but less than duloxetine (−14.3, −15.2) at week 12, with no significant difference at week 24 (p = 0.120). The CGI-I results paralleled the decrease of HAMD and HAMA, while the LS evaluation of gastrointestinal symptoms improved similarly in both groups, with no significant difference (p = 0.09).ConclusionDuloxetine is an efficient agent in the treatment of irritable bowel syndrome, because it decreases the mood symptoms more rapidly than SSRIs. The overall efficacy of SSRIs and duloxetine at 6 months is nevertheless similar.