Objective 7: Know the difference between tolerance, physical dependence and
addiction, and address patient/family/other health care provider concerns.
The fear that the use of opioids for pain relief will cause addiction is exaggerated in many health care professionals, and creates a significant barrier to good pain management.
Certainly, for terminally ill patients, it is extremely rare to see any such problems. Use of opioids in chronic pain not associated with terminal illness is more controversial and needs further study. This topic is not reviewed in this module.
It is useful to divide "addiction" concerns into four categories that are often confused:
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Tolerance is defined as a need for a larger dose of a medication to maintain the original effect. The development of clinically problematic tolerance is not common in the terminally ill.
It is important to remember that a need for increased doses may also represent a change in pain causes (new etiology, advancement of original process, etc.) requiring reassessment. This is often the reason for a need for increased doses in the terminally ill.
When tolerance does occur, it is easily managed by increasing the dose - tolerance to analgesic effect tends to parallel tolerance to toxic effects. An additional strategy is that of opioid rotation: changing from one opioid to another to try to achieve better pain relief with fewer side effects. When this is done, the new opioid should be started at no more than 50% of the calculated equianalgesic dose.
Cochrane review: Opioid switching to improve pain relief and drug tolerability
B. Physical Dependence
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Physical dependence is defined as development of withdrawal symptoms when opioids are discontinued abruptly or when opioid antagonists are administered. Like tolerance, this is a normal physiologic response (expected after 2 to 4 weeks of regular use).
Opioids are not unique in this regard. Many other medications (beta-blockers, alpha-2 agonists, SSRIs, etc.) also cause withdrawal symptoms, in many cases much more severe than opioids.
In cases where pain decreases during the course of an illness (as may happen after radiation to bone mets or corticosteroid treatment for increased intracranial pressure), most patients taper their opioid use over a short period without difficulty. It is generally recommended that the opioid be reduced by 50% every 2 or 3 days. Physical dependence is very seldom a clinical problem.
Fast Fact: Opioid Withdrawal
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Addiction is defined as a primary, chronic, neurobiologic disease with genetic, psychosocial, and environmental factors influencing it development and manifestations. It is characterized by behaviors that include one or more of the following:
- impaired control over drug use
- compulsive use
- continued use despite harm
Addiction is a serious disease, not a moral failing. Like other diseases, it is our obligation to diagnose and treat it.
to the Use of Opioids for the Treatment of Pain
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"The pseudoaddiction syndrome is initiated by inadequate pain management. Patients develop feelings of anger and isolation which lead to acting-out behavior. The health care team initially experiences frustration at not controlling the patient's complaint of pain combined with fears of inducing tolerance and dependence. Over time, they will seek to avoid contact with the patient as a means of reducing the source of conflict. Both cycles continually interact until a crisis based on mistrust ensues." (Weissman D, Haddox J. 1989)
Inadequate pain management as described above can leads to pseudoaddiction. Common forms of this inadequate pain management include: inadequate dosing of an analgesic, dosing intervals which are greater than the duration of action of a given analgesic, and prn dosing during continuous pain
Patients with unrelieved pain may become focused on obtaining medications, may “clock watch”, and may otherwise seem to be inappropriately “drug seeking”.
Key steps to abolishing pseudoaddiction include:
Fast Fact: Pseudoaddiction
- Trusting the patient's report of pain. Remember that pain is a subjective phenomenon.
- Using opioids appropriately based on the patient's report of pain. Important components of appropriate use include adequate dosing, appropriate intervals for administration, scheduled as well as prn dosing, and providing medication for breakthrough pain.
- Understanding the definition and risk of addiction
Next: Opioid Resistant Pain