Back to Journals » Journal of Pain Research » Volume 5

Comparison of pain models to detect opioid-induced hyperalgesia

Authors Krishnan, Salter, Sullivan, Gentgall, White, Rolan P

Received 28 October 2011

Accepted for publication 3 March 2012

Published 27 April 2012 Volume 2012:5 Pages 99—106

DOI https://doi.org/10.2147/JPR.S27738

Review by Single-blind

Peer reviewer comments 4


Sumithra Krishnan1, Amy Salter2, Thomas Sullivan2, Melanie Gentgall3, Jason White4, Paul Rolan1
1Discipline of Pharmacology, School of Medical Sciences, The University of Adelaide, 2Discipline of Public Health, The University of Adelaide, 3Pain and Anesthesia Research Clinic, Royal Adelaide Hospital, 4Pharmacy School, University of South Australia, Adelaide, South Australia, Australia

Objective: Chronic opioid therapy may be associated with hyperalgesia. Our objective was to determine if opioid-induced hyperalgesia detection sensitivity is dependent on the stimulus used to detect it.
Methods: This open design study compared the detection of hyperalgesia in opioid-dependent subjects (n = 16) and healthy control subjects (n = 16) using the following pain stimuli: cold pain, electrical stimulation, mechanical pressure, and ischemic pain. The opioid-dependent subjects were maintained on either methadone (n = 8) or buprenorphine (n = 8) for at least 3 months. None of the controls was dependent on opioids or other drugs of abuse.
Results: The opioid-dependent subjects were markedly more sensitive than controls to the cold pain test. Compared with the control group, the hazard ratio for ceasing the test due to intolerable pain was 7.7 (95% confidence interval [CI] 2.6–23.3) in the buprenorphine group and 4.5 (95% CI 1.7–15.6) in the methadone group, with similar data for the cold pain threshold. Of the remaining tests, there were differences only for the electrical pain threshold between treatment groups, with the geometric mean threshold in the buprenorphine group being 1.5 (95% CI 1.1–1.9)-fold higher (ie, less sensitive) than that of the controls; the geometric mean for the methadone group was 1.3 (95% CI 1.04–1.7)-fold higher than that of the controls. There were no significant differences between buprenorphine and methadone patients in test responses. Women were more sensitive to the cold pain (hazard ratio for tolerance, 3.1 [95% CI 1.4–7.3]) and ischemic tests (hazard ratio for tolerance, 2.7 [95% CI 1.2–6.1]). There were significant correlations between cold and ischemic tolerances (r = 0.50; P = 0.003) and between electrical and mechanical pain tolerances (r = 0.52; P = 0.002).
Conclusion: These findings indicate that cold pain is the most suitable of the methods tested to detect opioid-induced hyperalgesia. This is consistent with its sensitivity to detect opioid analgesia.

Keywords: opioid-induced hyperalgesia, opioid-dependent subjects, pain models

Creative Commons License This work is published and licensed by Dove Medical Press Limited. The full terms of this license are available at https://www.dovepress.com/terms.php and incorporate the Creative Commons Attribution - Non Commercial (unported, v3.0) License. By accessing the work you hereby accept the Terms. Non-commercial uses of the work are permitted without any further permission from Dove Medical Press Limited, provided the work is properly attributed. For permission for commercial use of this work, please see paragraphs 4.2 and 5 of our Terms.

Download Article [PDF]  View Full Text [HTML][Machine readable]