RESUMO
UNLABELLED: Selective serotonin reuptake inhibitors (SSRIs) exert beneficial effect on gastrointestinal tract (GIT), but its mechanism has not been recognized. One of the hypothesis assumes, that fluoxetine increases indirectly melatonin production. For this reason it can be hypothesized, that administration of drugs of opposite effect, for example tianepine (selective serotonin reuptake enhancer (SSRE), can reduce melatonin production resulting in harmful effects as regards GIT. The aim of the study was to confirm or reject this hypothesis. The study included 100 patients, aged 21-58 years, with irritable bowel syndrome (IBS). Basing on the Rome III Criteria patients with constipation-predominant (IBS-C, n=50) and with diarrhoea-predominant (IBS-D, n=50) and 25 health volunteers (control group C) were distinguished. Visual Analog Scale (VAS) and Hamilton Depression Rating Scale (HDRS) were used to determine the severity of somatic and psychic symptoms. The concentration of 6-sultatoxymelatonin (6-HMS) in the urine was measured by ELISA method. In both groups the patients were administrated tianeptine 12.5 mg three times daily or placebo for 8 weeks. After 8 weeks of tianeptine therapy no significant changes were found in urinary 6-HMS excretion both in IBS-C group (9.9±3.2 versus 11.5±3.5 µg/24 h) and in IBS-D group (11.8±3.3 versus 12.2±3.5 µg/24 h). Eight-week tianeptine therapy resulted in significant decrease of somatic and psychic symptoms in both investigated groups. The improvement in the quality of life indices was obtained in 76.5% of IBS-C and in 63.3% of IBS-D patients. CONCLUSIONS: tianeptine does not impair melatonin homeostasis in patients with IB, diminishes IBS symptoms and improves the patients' quality of life.