Anti-hyperalgesic effect of octreotide in patients with irritable bowel syndrome.
BACKGROUND
Octreotide has been found to be beneficial in the treatment of chronic pain, although the mechanisms underlying its therapeutic effect are incompletely understood.


OBJECTIVE
To assess the effect of octreotide on perceptual responses to rectal distension in irritable bowel syndrome patients and healthy controls at baseline and following the experimental induction of rectal hyperalgesia.


METHODS
In study 1, rectal perception thresholds for discomfort were determined in seven irritable bowel syndrome patients and eight healthy controls on three separate days using a computer-controlled barostat. Subjects received saline, low-dose and high-dose octreotide in a random double-blind fashion. In study 2, perceptual responses to rectal distension were obtained in nine irritable bowel syndrome patients and seven controls before and after repetitive high-pressure mechanical sigmoid stimulation.


RESULTS
Octreotide increased the discomfort thresholds in irritable bowel syndrome patients, but not in controls, without changing rectal compliance. Repetitive sigmoid stimulation resulted in decreased rectal discomfort thresholds in the patient group only. In irritable bowel syndrome patients, octreotide prevented the sensitizing effect of repetitive sigmoid stimulation on rectal discomfort thresholds.


CONCLUSIONS
Octreotide effectively increased discomfort thresholds in irritable bowel syndrome patients, but not in controls, at baseline and during experimentally induced rectal hyperalgesia. These findings suggest that octreotide exerts primarily an anti-hyperalgesic rather than analgesic effect on visceral perception.
Schwetz
I
I
CNS/WH: Center for Neurovisceral Sciences and Women's Health, Los Angeles, CA 90073, USA.
Naliboff
B
B
Munakata
J
J
Lembo
T
T
Chang
L
L
Matin
K
K
Ohning
G
G
Mayer
E A
EA
D000328:Adult; D000368:Aged; D012809:Colon, Sigmoid / Q000187:drug effects; D004311:Double-Blind Method; D005260:Female; D005765:Gastrointestinal Agents / Q000627:therapeutic use*; D006801:Humans; D006930:Hyperalgesia / Q000188:drug therapy*; D043183:Irritable Bowel Syndrome / Q000150:complications*; D008297:Male; D008875:Middle Aged; D015282:Octreotide / Q000627:therapeutic use*; D010147:Pain Measurement; D017288:Pain Threshold
D005765:Gastrointestinal Agents; D015282:Octreotide