To create this guideline, researchers in the Oregon Evidence-based Practice Center (EPC) at Oregon Health & Science University collaborated with the APS and AAPM for two years, reviewing more than 8,000 published abstracts and nonpublished studies to assess clinical evidence on which the new recommendations are based.
"This guideline was a true multidisciplinary effort that sought to address in a balanced manner the many challenging issues that clinicians face with regard to when and how to prescribe opioids for chronic noncancer pain," said Roger Chou, M.D., principal investigator; director of the American Pain Society Clinical Practice Guidelines Program; scientific director of the Oregon Evidence-Based Practice Center at OHSU; and associate professor of medical informatics and clinical epidemiology, and medicine (general internal medicine and geriatrics) in the OHSU School of Medicine.
"A key part of this process was performing a comprehensive literature review to inform the recommendations though an important take-home message is that even though the recommendations represent the best judgment of the panel based on the currently available literature, there is still a lot of research that needs to be done."
The expert panel concluded that opioid pain medications are safe and effective for carefully selected, well-monitored patients with chronic non-cancer pain. They made 25 specific recommendations and achieved unanimous consensus on nearly all.
Opioid prescribing has increased significantly due to growing professional acceptance that the drugs can relieve chronic non-cancer pain, and the guideline acknowledges there are widespread concerns about increases in prescription opioid abuse, addiction and diversion.
Opioids, such as morphine, oxycodone, oxymorphone and fentanyl are potent analgesics. They traditionally have been used to relieve pain following surgery, from cancer and at the end of life. Today opioids are used widely to relieve severe pain caused by chronic low-back injury, accident trauma, crippling arthritis, sickle cell, fibromyalgia, and other painful conditions.
Prior to initiating chronic opioid therapy, the guideline advises clinicians to determine if the pain can be treated with other medications. If opioids are appropriate, the clinician should conduct a thorough medical history and examination and assess potential risk for substance abuse, misuse or addiction.
Diligent Patient Monitoring Is Essential
A key recommendation urges clinicians to continuously assess patients on chronic opioid therapy by monitoring pain intensity, level of functioning and adherence to prescribed treatments. Periodic drug screens should be ordered for patients at risk for aberrant drug behavior.
Other recommendations in the APS/AAPM clinical practice guideline include:
- Methadone: Use of methadone for pain management has increased dramatically but few trials have evaluated its benefits and harms for treatment of chronic non-cancer pain. Methadone, therefore, should be started at low doses and titrated slowly. Because of its long half-life and variable pharmacokinetics, the panel recommends methadone not be used to treat breakthrough pain or as an as-needed medication.
- Abusers: Chronic opioid therapy must be discontinued in patients known to be diverting their medication or in those engaging in serious aberrant behaviors.
- Breakthrough Pain: As-needed opioids can be prescribed based on initial and ongoing analysis of therapeutic benefit versus risk.
- High Doses: Patients who need high doses of opioids (200 mg daily of morphine or equivalent) should be evaluated for adverse events on an ongoing basis, and clinicians should consider rotating pain medications when patients experience intolerable side effects or inadequate benefit despite appropriate dose increases.
- Driving and Work Safety: Patients should be educated about the greater risk for impairment when starting chronic opioid therapy and counseled not to drive or engage in potentially dangerous work if impaired.
- Pregnancy: Clinicians should counsel women about risks of opioids in pregnancy and encourage minimal or no use of chronic opioid therapy unless potential benefits outweigh risks.
The guideline on opioid therapy for chronic non-cancer pain is the first such collaboration between APS and AAPM. It is the sixth evidenced-based, pain management clinical practice guideline published by APS. Others have covered sickle-cell disease, arthritis, cancer, fibromyalgia, and low back pain.