The American Society of Anesthesiologists Task Force on Chronic Pain Management and the American Society of Regional Anesthesia and Pain Medicine recently published updated practice guidelines for the management of chronic pain. They have been a long time in coming, as the last such document was presented to the public almost 15 years ago.
Since the mid-1990s, there have been a variety of advances and new drugs for the treatment of chronic pain; but chronic pain has by no means been eliminated. By some measures (such as the proliferation in the marketplaces-both legal and illegal-of prescription pain medications), one could make an argument that chronic pain in these United States is becoming more prevalent, and perhaps even more intransigent; perhaps a manifestation of the chronic dissatisfaction and depression that seems to have become a part of living for so many.
So, let us review what the specialists have to say about easing the pain from a pharmacologic perspective, keeping in mind that, as with so many chronic illnesses and syndromes, a cure might be too much to expect. Further, keep in mind that the studies in which many of these drugs were evaluated were for a few weeks or months---not the lifetime of a chronic pain patient.
1. Anticonvulsants. It is strongly agreed that certain types of anticonvulsants be used for neuropathic pain.
2. Antidepressants. Tricyclic antidepressants provide effective pain relief for a variety of chronic pain etiologies, and it is strongly agreed that these drugs continue to be used for chronic pain. Likewise, selective serotonin-norepinephrine reuptake inhibitors provide effective relief for chronic pain.
3. Benzodiazepines. The members of the task force were hesitant to embrace the use of benzodiazepines for chronic pain, although some studies have shown benefit for neurologic pain syndromes.
4. NMDA receptor antagonists. Agents such as dextromethorphan have been studied in patients with diabetic neuropathy, postherpetic neuralgia, and other neuropathic pain conditions (phantom limb pain, chronic regional pain syndrome, etc.); unfortunately, the results have been equivocal, but it appears that NMDA receptor antagonists may afford some benefit to those with neuropathic pain.
5. NSAIDs. These anti-inflammatory drugs appear most effective in patients with chronic back pain.
6. Opioids. Extended release opioid therapy provides effective pain relief for patients with low back pain or neuropathic pain. Immediate release opioids provide relief for back, neck, leg and neuropathic pain.
7. Skeletal muscle relaxants. Studies are not sufficient to recommend these based on "the science"; still, the pain specialists feel these drugs play a role in making chronic pain more tolerable.
8. Topical agents. Capsaicin and lidocaine appear to have an equivocal effect in patients with neuropathic pain; but the specialists do feel these drugs can and should be tried for patients with, for example, diabetic neuropathy and postherpetic neuralgia.
In conclusion, it would appear that when it comes to chronic pain, an attempt at treatment is an important part of therapy, even if the statistics do not firmly support the use of a particular drug. Let's hope the side effect profile is just as obliging.