Gabapentin reduces rectal mechanosensitivity and increases rectal compliance in patients with diarrhoea-predominant irritable bowel syndrome.
BACKGROUND
Gabapentin has been shown to reduce elements of central sensitization in human experimental hyperalgesia. It remains uninvestigated whether gabapentin has beneficial effects for irritable bowel syndrome associated with visceral hypersensitivity.


OBJECTIVE
To evaluate the effects of gabapentin on sensory and motor function of the rectum in patients with diarrhoea-predominant irritable bowel syndrome.


METHODS
Forty patients with diarrhoea-predominant irritable bowel syndrome completed this randomized, double-blind, placebo-controlled, parallel-grouped study. All patients received a barostat study and were subsequently randomized for 5-day treatment with gabapentin 300 mg/day and then 600 mg/day or placebo. On day 6, after subjects had their morning dose, the barostat experiment was repeated.


RESULTS
The threshold pressures for bloating, discomfort and pain significantly increased after gabapentin, but not after placebo. Significant increase in the pressure and corresponding wall tension inducing discomfort or pain were observed in the gabapentin group, but not in the placebo group. Rectal compliance significantly increased after gabapentin, but not after placebo. The postprandial increase of rectal tone was not affected by gabapentin.


CONCLUSIONS
Our results show that gabapentin reduces rectal sensory thresholds through attenuating rectal sensitivity to distension and enhancing rectal compliance in diarrhoea-predominant irritable bowel syndrome patients. The clinical efficacy of this drug in irritable bowel syndrome patients warrants investigation.
Lee
K J
KJ
Department of Gastroenterology, Ajou University School of Medicine, Suwon, Korea. kjleemd@hotmail.com
Kim
J H
JH
Cho
S W
SW
D000328:Adult; D000588:Amines / Q000008:administration & dosage*; D000700:Analgesics / Q000008:administration & dosage*; D003187:Compliance; D003509:Cyclohexanecarboxylic Acids / Q000008:administration & dosage*; D003967:Diarrhea / Q000188:drug therapy / Q000503:physiopathology*; D004311:Double-Blind Method; D000077206:Gabapentin; D006801:Humans; D043183:Irritable Bowel Syndrome / Q000188:drug therapy / Q000503:physiopathology*; D010147:Pain Measurement / Q000187:drug effects; D012007:Rectum / Q000187:drug effects* / Q000502:physiology; D012684:Sensory Thresholds / Q000187:drug effects*; D011795:Surveys and Questionnaires; D005680:gamma-Aminobutyric Acid / Q000008:administration & dosage*
D000588:Amines; D000700:Analgesics; D003509:Cyclohexanecarboxylic Acids; D005680:gamma-Aminobutyric Acid; D000077206:Gabapentin