Understanding opioid tolerance in cancer pain.
OBJECTIVE
To review opioid tolerance in chronic cancer pain, define the phenomenon and its scope, review physiologic mechanisms, and discuss clinical strategies to identify and manage this complex issue.


METHODS
Review articles, case studies, original research, and published guidelines.


RESULTS
Novel therapies to prevent/reverse tolerance are being investigated with a possible future role for N-methyl-d-aspartate antagonists.


CONCLUSIONS
Greater nursing research is needed to identify patient risk factors for tolerance development and clinical measurement of the phenomenon. Understanding cellular mechanisms for tolerance may contribute to better management.


CONCLUSIONS
Nursing knowledge of tolerance is important to provide the basis for accurate patient assessment, education, and pain management.
Cady
J
J
Department of Anesthesiology, Virginia Mason Medical Center, Seattle, WA, USA. jormain.cady@vmmc.org
D000701:Analgesics, Opioid / Q000494:pharmacology*; D002908:Chronic Disease; D004361:Drug Tolerance / Q000502:physiology; D006801:Humans; D016202:N-Methylaspartate / Q000037:antagonists & inhibitors; D009369:Neoplasms / Q000150:complications*; D009730:Nursing Assessment; D009859:Oncology Nursing / Q000379:methods; D010146:Pain / Q000188:drug therapy* / Q000209:etiology* / Q000451:nursing / Q000503:physiopathology; D010147:Pain Measurement; D010353:Patient Education as Topic; D015995:Prevalence; D011957:Receptors, Opioid / Q000187:drug effects / Q000502:physiology; D012307:Risk Factors
D000701:Analgesics, Opioid; D011957:Receptors, Opioid; D016202:N-Methylaspartate