Guidelines for Prescribing Opioids for Chronic Pain

Although it is now widely accepted that opioids have an important place in the management of chronic noncancer pain, many physicians are still concerned about prescribing these medications for this problem. To assist in optimizing the use of opioids, the American Pain Society and the American Academy of Pain Medicine jointly issued clinical guidelines for prescribing these agents along with reviews of the literature on predicting aberrant drug-related behaviors and gaps in research.^1-3

The guidelines address multiple issues, including the management of opioid-related adverse effects and the use of opioids in pregnancy. Here I review these guidelines and focus on the areas of most importance to mental health professionals.

Evaluating patients for chronic opioid therapy

The guidelines highlight the importance of “including an assessment of risk of substance abuse, misuse, or addiction”^1(p115) when evaluating patients for chronic opioid therapy (COT), although they acknowledge that many physicians have limited skills in doing so. The guidelines panel noted that clinicians who prescribe COT “should routinely integrate psychotherapeutic interventions”^1(p121) for the patients receiving it.

In the United States, most physicians who focus on pain management are anesthesiologists; therefore, it is probably unrealistic to expect a significant improvement in either of these areas (ie, risk assessment and the integration of psychotherapeutic interventions) in the foreseeable future. This is not a criticism of anesthesiologists but rather a recognition that they are being asked to do something for which their training provides little education (even for those who have completed fellowships in pain management). Asking an anesthesiologist to evaluate a patient for opioid abuse is akin to asking a psychiatrist to perform a preoperative anesthesiology evaluation.

The guidelines panel evaluated several screening instruments for predicting and identifying aberrant drug-related behavior; they included 2 versions of the Screener and Opioid Assessment for Patients With Pain, the Current Opioid Misuse Measure, and the Opioid Risk Tool.² While the panel did believe these tools may, at times, provide some useful information on patients being treated for chronic pain, it found little actual research to support this view. Not surprisingly, the panel found that the factor that most strongly predicts aberrant drug-taking behavior is a personal or family history of substance abuse.

For patients who are at high risk for aberrant drug-related behaviors, the guidelines recommend periodic urine drug screens. The guidelines also recommend using urine screens or other tests to confirm adherence to treatment for patients who are not identified as being at high risk. They do note, however, that there is limited research demonstrating that urine drug screens have much of an effect on preventing these behaviors among patients receiving COT or in improving pain management.

Unfortunately, on the basis of my experience, the screening instruments and urine drug screens often are used in place of another recommendation in the guidelines: monitoring not only pain but also the level of functioning and the achievement of therapeutic goals. I personally believe that nothing can replace talking with patients and continuously reviewing both of these. Of course, this can take substantial amounts of time, but it is the only way to obtain as clear a view as possible about whether a patient is benefiting from treatment. Clinicians who prescribe COT for chronic pain must always be suspicious when a patient reports a reduction in pain but no accompanying improvement in function or progress toward achieving identified goals.

Choosing opioids and dosing

The guidelines note that there is little research to assist physicians in choosing either an opioid with which to initiate treatment or an optimal initial dosing. Instead, they suggest simply following the general recommendation of starting low and titrating slowly-especially in geriatric patients or in those with other health problems. Although the guidelines support the general view that it is better to initiate therapy with a short-acting rather than a long-acting opioid and to choose an around-the-clock fixed dosing schedule instead of as-needed dosing, there is also limited literature on these subjects.

With regard to dosing when switching from one opioid to another, the guidelines advise a conservative approach and note that standard conversion tables are inexact. A reduction of the apparent dosage of the new opioid by 25% to 50% and then titration as indicated are recommended.

The need for more research

All of the above highlights what is perhaps the most surprising finding of all. Despite the number of patients who are being treated with COT and the length of time that opioids have been employed for chronic pain, much research remains to be done. In fact, none of the 25 specific recommendations made in the guidelines were supported by what the panel considered to be high-quality evidence, and as few as 4 were supported by only moderate-quality evidence. Virtually all of the studies of the benefits and harms associated with COT lasted 16 weeks or less-a relatively short period when one considers that many patients receiving this therapy may require it for years.

Obviously, problems of abuse and addiction may not develop or, if they are present, may not become apparent during the first 16 weeks of treatment-especially when one considers that the therapeutic interventions are not usually focused on them. Furthermore, most of these studies also excluded patients considered at higher risk for opioid abuse. Thus it is difficult to determine when the potential benefits of COT outweigh the palpable risks or which opioids would be the best choice if COT is indicated.

References:

References

1. Chou R, Fanciullo GJ, Fine PG, et al; American Pain Society–American Academy of Pain Medicine Opioids Guidelines Panel. Clinical guidelines for the use of chronic opioid therapy in chronic noncancer pain. J Pain. 2009;10:113-130.
2. Chou R, Fanciullo GJ, Fine PG, et al. Opioids for chronic noncancer pain: prediction and identification of aberrant drug-related behaviors: a review of the evidence for an American Pain Society and American Academy of Pain Medicine clinical practice guideline. J Pain. 2009;10:131-146.
3. Chou R, Ballantyne JC, Fanciullo GJ, et al. Research gaps on use of opioids for chronic noncancer pain: findings from a review of the evidence for an American Pain Society and American Academy of Pain Medicine clinical practice guideline. J Pain. 2009;10:147-159.