Melatonin improves bowel symptoms in female patients with irritable bowel syndrome: a double-blind placebo-controlled study.
BACKGROUND
Melatonin is involved in the regulation of gastrointestinal motility and sensation.


OBJECTIVE
To determine the potential therapeutic effects of melatonin in irritable bowel syndrome (IBS).


METHODS
Seventeen female patients satisfying the Rome II criteria for IBS were randomized to receive either melatonin 3 mg nocte or identically appearing placebo 1 nocte for 8 weeks, followed by a 4-week washout period and placebo or melatonin in the reverse order for another 8 weeks. Three validated questionnaires - the GI symptom, the sleep questionnaires and the Hospital Anxiety and Depression Scale - were used to assess symptom severity and to compute the IBS, sleep and anxiety/depression scores, respectively.


RESULTS
Improvements in mean IBS scores were significantly greater after treatment with melatonin (3.9 +/- 2.6) than with placebo (1.3 +/- 4.0, P = 0.037). Percent response rate, defined as percentage of subjects achieving mild-to-excellent improvement in IBS symptoms, was also greater in the melatonin-treated arm (88% vs. 47%, P = 0.04). The changes in mean sleep, anxiety, and depression scores were similar with either melatonin or placebo treatment.


CONCLUSIONS
Melatonin is a promising therapeutic agent for IBS. Its therapeutic effect is independent of its effects on sleep, anxiety or depression.
Lu
W Z
WZ
Department of Pharmacology, National University of Singapore.
Gwee
K A
KA
Moochhalla
S
S
Ho
K Y
KY
D000328:Adult; D000368:Aged; D001007:Anxiety / Q000188:drug therapy / Q000209:etiology; D003866:Depressive Disorder / Q000188:drug therapy / Q000209:etiology; D004311:Double-Blind Method; D005260:Female; D005765:Gastrointestinal Agents / Q000627:therapeutic use*; D006801:Humans; D043183:Irritable Bowel Syndrome / Q000150:complications / Q000188:drug therapy*; D008550:Melatonin / Q000627:therapeutic use*; D008875:Middle Aged; D012893:Sleep Wake Disorders / Q000188:drug therapy / Q000209:etiology; D011795:Surveys and Questionnaires
D005765:Gastrointestinal Agents; D008550:Melatonin