One of my patients is a 55-year-old man in good health except for chronic low back pain. His back pain was stable, with intermittent flares that were controlled by receiving acetaminophen/hydrocodone (Xodol) tablets. However, in the past several months his focal back pain has intensified, absent any radicular symptoms, leading him to accelerate his use of pain medication. With his complaints of daily, severe pain, I recently had the patient sign a pain agreement that includes a stipulation about no early prescription refills. Because he has no red flags for prescription drug abuse, I prescribed methadone, 5 mg three times daily, and acetaminophen/hydrocodone for “breakthrough” pain. He now comes to my clinic frustrated and upset, having run out of both pain medications early and asking for refills. I have always had a good working relationship with him and he trusts my professional expertise. When I ask him how he has been spending his time, he replies, “In bed, it just hurts too much and I don't feel like I'll ever be healthy again.” I am not exactly sure what to do next to help this patient.
This case encapsulates many of the significant challenges in providing care for patients with chronic noncancer pain. There is an absence of adequate research (particularly well-designed, longer-term, randomized controlled trials) to guide therapy.1 The lack of curative therapy, compounded by the lack of precise measures to gauge patient improvement, complicates treatment decisions. Complex comorbidities (including depression) often accompany chronic non-cancer pain and exacerbate the patient's sense of helplessness. Physicians are reasonably concerned that they are being manipulated by exaggerated pain complaints in the interest of secondary gain, including problems of prescription drug abuse.
In the case scenario above, the key to improved care and satisfaction in the primary care setting is to use a multifaceted approach that takes a long-term perspective (e.g., distinguishing chronic noncancer pain's chronicity from acute pain or the pain of malignancy) and adheres to negotiated treatment boundaries. In general, most patients with chronic pain have had extensive previous evaluations.2 A change in the status of chronic pain is an opportunity for the physician to comprehensively review the patient's previous work-ups. The physician should pursue additional testing to eliminate reversible physical causes only if there are gaps in the previous evaluation or if there has been a significant change from baseline.
Although documenting ongoing assessment of the pain is necessary, particularly when prescribing opioids, physicians must recognize that pain severity is only one part of the overall evaluation. In fact, it is important to address all components of the problem from the biopsychosocial perspective, particularly in recognizing that psychiatric comorbidity and substance abuse are common.
In the setting of chronic noncancer pain, studies document lifetime prevalence rates of 50 percent for depression, 20 percent for anxiety, 40 percent for alcohol abuse or dependence, and 30 percent for opioid abuse or dependence.2 A World Health Organization (WHO) survey of primary care patients in 15 countries reported that patients with chronic pain had more than four times the odds of having anxiety or a depressive disorder.3 A comprehensive literature review of depression and pain comorbidity summarized that the concurrent prevalence of major depression with chronic noncancer pain is as high as 85 percent.4
The combination of depression and pain is associated with worse clinical outcomes than either condition alone.4 The reciprocal nature of the depression-pain relationship further highlights the critical importance of screening all patients with chronic noncancer pain for affective disorders using available screening tools, such as the Beck Depression Inventory.5 Physicians are advised to say to patients, “I do not think your pain is psychological, but because depression can act as a magnifying glass for your pain, it is important that I ask you questions about your overall mood.”
Notably, follow-up analysis of the WHO survey found a strong and symmetrical relationship between persistent pain and psychological disorder.6 Most significantly, impairment of daily activities appeared to be a central component of that relationship, highlighting that additional psychosocial history must include an assessment of functional status with a focus on routine daily activities.
Nonpharmacologic approaches for managing chronic noncancer pain include alternative therapies, such as acupuncture and massage. There is evidence that acupuncture, added to other conventional therapies, relieves chronic low back pain and improves function better than conventional therapies alone, although the magnitude of the effects are generally small.7 The beneficial effects of massage in patients with chronic low back pain may last up to one year.8
Although there is increasing evidence about the benefit of these alternative therapies, the mainstay of non-pharmacologic approaches is physical exercise. Clinical data demonstrate the benefit of exercise, particularly for chronic low back pain and fibromyalgia.9,10 Experts postulate that exercise may help by retraining the nervous system to re-establish normal neural pathways affected by chronic pain. Having the patient keep a daily diary of physical activity is helpful in assessing adherence.
Lastly, the addition of antidepressant therapy deserves special attention. The established relationship between depression and chronic pain is highlighted above. Meta-analyses and systematic reviews have demonstrated the analgesic effectiveness of antidepressant medications (especially tricyclic antidepressants) across a broad range of underlying conditions.4,11 Furthermore, depression in the setting of chronic pain, as in other settings, is probably undertreated. Therefore, antidepressant therapy should be considered in all patients with chronic noncancer pain and clinical depression and, additionally, in all patients with chronic pain who have not responded adequately to other therapies. Other pharmacologic approaches are available, but are beyond the scope of this commentary.12
In the case scenario above, plain film radiographs and a sedimentation rate evaluation may be useful, given that the patient is older than 50 years and his pain has become more severe.13 If these tests return normal, the physician should continue the methadone, with a slight increase in dosage, and also obtain an electrocardiogram to monitor for QT prolongation,14 but consider discontinuing the “breakthrough” short-acting opioids because continued use may reinforce the role of pain medication rather than distract the patient from the experience of the pain.
Continued prescription of opioids should be contingent upon the agreement of no further violations of a pain management plan and an increase in daily physical activity, starting with a simple walking program documented in an exercise diary. If the patient is amenable to physical therapy, that is also an option. The physician should encourage this patient to try a tricyclic antidepressant (monitoring for drug interactions with methadone) or a newer antidepressant agent, certainly if a depression screening tool reveals major depression. If the pain continues, a trial of acupuncture or massage therapy should be instituted in addition to the above steps. Short-term, regular (e.g., every two weeks) follow-up is in order during the period of stabilization.