Differential effect of opioids in patients with chronic pancreatitis: an experimental pain study.
OBJECTIVE
Animal experiments and clinical observations have indicated a different working profile of oxycodone compared to morphine, and it has previously been shown that oxycodone attenuates visceral pain better than morphine. The objective of this study was to test the effects of oxycodone and morphine on experimental pain in patients with pain caused by chronic pancreatitis.


METHODS
Ten patients took part in this blinded, cross-over study. The analgesic effects of morphine (30 mg, oral), oxycodone (15 mg, oral) and placebo were tested against multimodal (mechanical, thermal and electrical) experimental pain in the skin, muscles and oesophagus. Pain was assessed at baseline and 30, 60 and 90 min after drug administration.


RESULTS
In the skin and muscles, oxycodone was more effective than placebo and morphine on mechanically (skin: F=12.4, p<0.001, muscle: F=11.0, p<0.001) and thermally (skin: F=8.5, p<0.001) evoked pain. In oesophageal heat pain, the effect of morphine was equal to that of placebo, while oxycodone attenuated pain better than both morphine and placebo (F=9.5, p<0.001). Both morphine and oxycodone were more effective in attenuating mechanical pain in the oesophagus than placebo (F=8.6, p<0.001). After electrical stimulation no differences were seen between the opioids and placebo in any tissue studied.


CONCLUSIONS
Oxycodone was a stronger analgesic than morphine in several pain modalities in the skin, muscle and oesophagus.
Staahl
Camilla
C
Centre for Visceral Biomechanics and Pain, Department of Gastroenterology, University Hospital Aalborg, Denmark.
Dimcevski
Georg
G
Andersen
Søren Due
SD
Thorsgaard
Niels
N
Christrup
Lona L
LL
Arendt-Nielsen
Lars
L
Drewes
Asbjørn Mohr
AM
D000328:Adult; D000701:Analgesics, Opioid / Q000009:adverse effects / Q000494:pharmacology* / Q000627:therapeutic use; D000704:Analysis of Variance; D018592:Cross-Over Studies; D003718:Denmark; D004311:Double-Blind Method; D004558:Electric Stimulation / Q000009:adverse effects; D004947:Esophagus / Q000187:drug effects / Q000503:physiopathology; D005260:Female; D006358:Hot Temperature / Q000009:adverse effects; D006801:Humans; D008297:Male; D008875:Middle Aged; D009020:Morphine / Q000494:pharmacology* / Q000627:therapeutic use; D018482:Muscle, Skeletal / Q000187:drug effects / Q000503:physiopathology; D010098:Oxycodone / Q000494:pharmacology* / Q000627:therapeutic use; D010146:Pain / Q000188:drug therapy* / Q000209:etiology* / Q000503:physiopathology; D010147:Pain Measurement; D017288:Pain Threshold / Q000187:drug effects; D050500:Pancreatitis, Chronic / Q000150:complications*; D015203:Reproducibility of Results; D012867:Skin / Q000187:drug effects / Q000503:physiopathology; D013314:Stress, Mechanical; D016896:Treatment Outcome
D000701:Analgesics, Opioid; D009020:Morphine; D010098:Oxycodone