The role of long-term opioid therapy for chronic nonmalignant pain is evolving. Pain specialists now strongly endorse the view that opioid therapy can be safe and effective in a subgroup of patients with chronic pain. This acceptance must be balanced by the acknowledgement that side effects often are a problem and that the drugs may become the objects of abuse and even addiction in predisposed individuals. Any clinician who wants to be able to provide selected patients with this therapy must acquire basic skills in both the principles of opioid prescribing and the assessment and management of risk.

Some types of neuropathic pain may be relatively less responsive to opioid drugs, but the claim that these syndromes are opioid resistant, which has appeared in the literature, is incorrect. There are randomized controlled trials demonstrating the efficacy of morphine, oxycodone, levorphanol, and tramadol in various types of neuropathic pain. There have been positive randomized, placebo-controlled trials of oxycodone and tramadol in diabetic painful polyneuropathy. In the study of controlled-release oxycodone, study medication was titrated every 3 days until the preferred maximum dose was attained. At an average dose of 37 mg/day (range 0-99 mg/day), the opioid provided significantly more analgesia than placebo, as evidenced by better pain scores, more satisfaction with medication, and significant decreases in pain interference with social relationships, enjoyment of life, and quality of sleep.

The selection and management of long-term opioid therapy for chronic nonmalignant pain should be guided by a set of principles that help define the selection criteria, the need for individualization of the dose, and the structure for monitoring.

Considerations in the Use of Opioid Therapy for Chronic Pain

1. Patients with moderate to severe pain may be potential candidates for opioid therapy. Physicians can formulate a clinical judgment based on responses to the following questions:
• What is the likelihood that opioid therapy will be effective based on past clinical experience, pertinent medical literature, and characteristics of the pain (i.e., etiology and pathophysiology)?
• Are other therapies likely to work as well, and have there been adequate trials of those therapies with this patient?
• What are the risks of opioid therapy in this patient, and do the likely benefits of opioid therapy outweigh the potential risks?
• Is the patient likely to demonstrate responsible drug taking?



2. If the evaluation raises concerns about the appropriateness of therapy or a suitable way to monitor therapy, consider referral to a pain management program or addiction medicine specialist for advice before initiating therapy.
   
   
3. A single clinician, who has reviewed all medical records, should take primary responsibility for opioid prescriptions; the prescriber should have the skills necessary to optimize the therapy according to accepted principles and guidelines, and perform risk assessment and management on an ongoing basis.
   
   
4. Patients need to be educated about opioid therapy, and clinicians should document the consent discussion, which might cover:
• the need for monitoring and adherence to instructions
• information about physical dependence and addiction
• the potential for side effects (e.g., cognitive impairment and constipation)
• Some clinicians use an opioid agreement as a tool to inform patients about the structure for therapy, the nened for adherence and the consequences of nonadherence; other clinicians do not endorse the use of this tool, but document the consent discussion and rely on subsequent communication with the patient to provide the education and oversight.
  
  
5. Therapy can start after the provider performs a clinical evaluation of potential risk associated with abuse or addiction. This provides a structure to the therapy that enforces a degree of control and monitoring that is commensurate with the perceived risk.
   
   
6. Opioid therapy should be implemented according to well-accepted principles for prescribing, including a comprehensive pain assessment, selection of an appropriate drug and route, individualization of the dose by repeated dose titration, assessment and treatment of common side effects, and monitoring of outcomes over time.
   
   
7. Patients may need access to a “rescue dose” for breakthrough pain. This decision should be made on a case-by-case basis after assessment of the pain syndrome, opioid requirements, and the likelihood of responsible drug use. If rescue doses are not prescribed, patients may take one or two extra doses on a day of increased pain, which must be followed by an equal reduction of doses on subsequent days.
   
   
8. At each encounter, the healthcare provider should thoroughly assess and document the following:
• comfort (degree of analgesia)
• opioid-related side effects
• functional status (physical and psychosocial)
• occurrence of problematic drug-related behaviors



9. Providers should reassess patients with no substantial prior opioid exposure who fail to achieve at least partial analgesia at relatively low initial doses of an opioid. This failure raises questions about the potential treatability of the pain syndrome with opioids. Some patients are outliers with severe pain, who respond appropriately to dose escalation; others, however, demonstrate responses that raise questions about the effectiveness or appropriateness of opioid therapy. Recognize the variations in responsiveness.
   
   
10. Although providers should continually stress improvement in function, they should accept meaningful partial analgesia without a decline in function as the appropriate minimal goal of therapy. They will emphasize attempts to capitalize on improved analgesia by gains in function. Opioid therapy is only one of multiple modalities that can be used.
    
    
11. If problematic drug-related behaviors occur, the clinician will carefully assess the patient to better understand the factors that contribute and the existence of any psychiatric or medical comorbidities. Depending on the assessment, some patients are best managed by tapering and discontinuing the opioid therapy, and others may appropriately continue therapy within rigid guidelines. Clinicians may consider consultation with an addiction medicine specialist.