Journal of Pain & Palliative Care Pharmacotherapy. 2013;27:392–393. ISSN: 1536-0288 print / 1536-0539 online DOI: 10.3109/15360288.2013.847518

EUROPEAN PERSPECTIVES ON PAIN AND PALLIATIVE CARE

Defining Opioid Tolerance and Dependency J Pain Palliat Care Pharmacother Downloaded from informahealthcare.com by The University of Manchester on 11/12/14 For personal use only.

C´esar Margarit Ferri This report is adapted from paineurope 2013; Issue 2, ©Haymarket Medical Publications Ltd., and is presented with permission. paineurope is provided as a service to pain management by Mundipharma International, LTD. and is distributed free of charge to healthcare professionals in Europe. Archival issues can be accessed via the website: http://www.paineurope.com at which European health professionals can register online to receive copies of the quarterly publication.

Although opioids have been used to treat patients with chronic cancer and noncancer pain for many years, when opioids are initiated it can highlight the lack of knowledge regarding some aspects of opioid therapy for both physicians and patients. One of the most important areas is the confusion surrounding the definitions of opioid tolerance and opioid dependency. Existing criteria which relate to substance dependence (the term used in preference to “addiction”) have poor applicability when patients are using opioids for pain relief, and the criteria have acted as a source of concern to physicians, patients and carers.1

Tolerance is defined as a loss of analgesic potency that leads to ever-increasing dose requirements and decreasing effectiveness over time.3 Exposure to a drug (the opioid) induces changes that result in a diminution of one or more of the drug’s effects over time. There are two types of tolerance: innate (genetically determined) and acquired (pharmacokinetic, pharmacodynamic and learned). In contrast to analgesic tolerance, tolerance to opioid-induced sideeffects is a desirable consequence of long-term treatment, facilitating upward dose titration to attain satisfactory pain relief.4 Addiction is a more complicated illness: it is a primary, chronic, neurobiological disease with genetic, psychosocial and environmental factors influencing its development and manifestation.2 Addiction is comprised of four core elements (the four C’s):2

Definitions Substance abuse problems can be divided into two categories: dependence and abuse. Addiction and physical dependence are not the same; any patient taking opioids has the potential to develop physical dependence and may suffer withdrawal symptoms upon the discontinuation of the opioid.2

• compulsive use, • inability to control the quantity used, • craving the psychological drug effects and • continued use of the drug despite its adverse effects. Addiction should not be confused with physical dependence which is a drug class-specific withdrawal syndrome (for example: pain, insomnia, tachycardia, tachypnea and diarrhea) that is produced by the abrupt cessation of a drug, a rapid dose reduction, a decreasing blood level of the drug and/or the administration of an antagonist.2 In the past, patients who had nonoptimal pain control using medication and who instigated unauthorized dose escalation were misdiagnosed as addicts (pseudoaddiction); the

Dr C´esar Margarit Ferri is Chief of the Pain Unit at the AnesthesiologyCritical Care-Pain Medicine Department, Alicante Hospital, University of Miguel Hernandez, Alicante, Spain. This report is adapted from paineurope 2013; Issue 2, ©Haymarket Medical Publications Ltd., and is presented with permission. paineurope is provided as a service to pain management by Mundipharma International, LTD. and is distributed free of charge to healthcare professionals in Europe. Archival issues can be accessed via the website: http://www.paineurope.com at which European health professionals can register online to receive copies of the quarterly publication. Address correspondence to: C´esar Margarit Ferri, Anesthesiology-Critical Care-Pain Medicine Department, Alicante Hospital, University of Miguel Hernandez, Alicante, Spain. (E-mail: [email protected])

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difference is that when pain is controlled this behavior disappears.2

J Pain Palliat Care Pharmacother Downloaded from informahealthcare.com by The University of Manchester on 11/12/14 For personal use only.

Communication When prescribing opioids, doctors and patients should discuss the goals of treatment, what a successful opioid trial outcome would be, what an unsuccessful trial looks like, as well as the further options available if the trial is unsuccessful.5 The aim is to alleviate patient fears including “What happens if I’m opioid tolerant?” and “Will I become an addict?”. This kind of comprehensive assessment is appreciated by patients, providing an understanding of the goals of treatment, the secondary effects and the monitoring program.5

TABLE 1.

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Principles of opioid therapy.

Principle Careful selection of patients Individualized information Caution in dose escalation, follow guideline recommendations Taper and discontinue if no benefit Detect misuse, abuse and tolerance

Management approach Screening tools/risk factors Informed consent Monitoring, urine tests Follow up Referral to secondary care if needed

Declaration of interest: The authors report no declarations of interest. The authors alone are responsible for the content and writing of the paper.

REFERENCES Treatment Physicians should treat their patients according a balanced multi modal treatment strategy where established monitoring and global follow up are mandatory.6 The risks and benefits of opioid therapy should be adequately explained to both patients and their carers. Three important principles to follow are:7

• titration: titrate against analgesic response and sideeffects (with regular assessment), • tailoring: treatment should be individualized and • tapering: controlled decrease of any opioid treatment which does not improve pain despite adequate trial (Table 1). Screening tools may be useful in identifying patients with risk factors for addiction who will need closer follow-up.7

[1] Stannard C. All party parliamentary group on drug misuse inquiry response on behalf of the British Pain Society. Risk of Addiction to Opioids Prescribed for Pain Relief. London, British Pain Society, 2007. [2] Jan SA. Introduction: landscape of opioid dependence. J Manag Care Pharm. 2010;16(1 Suppl B):S4–S8. [3] Benyamin R, Trescot AM, Datta S, Buenaventura R, Adlaka R, Sehgal N, et al.Opioid complications and side effects. Pain Physician. 2008;11(2 Suppl):S105–S120. [4] Adriaensen H, Vissers K, Noorduin H, Meet T. Opioid tolerance and dependence: an inevitable consequence of chronic treatment? Acta Anaesthesiologica Belgica. 2003;54(1):37–47. [5] Pohl M, Smith L. Chronic pain and addiction: challenging cooccurring disorders. J Psychoactive Drugs. 2012;44(2):119–124. [6] Snidvongs S, Mehta V. Recent advances in opioid prescription for chronic non-cancer pain. Postgrad Med J. 2012;88(1036):66–72. [7] Kahan M, Wilson L, Mailis-Gagnon A, Srivastava A. National Opioid Use Guideline Group. Canadian guideline for safe and effective use of opioids for chronic noncancer pain: clinical summary for family physicians. Part 2: special populations. Can Fam Physician. 2011;57(11):1269–1276.

Defining opioid tolerance and dependency.

This report is adapted from paineurope 2013; Issue 2, ©Haymarket Medical Publications Ltd., and is presented with permission. paineurope is provided a...
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