Chronic Pain?

Chronic Pain?

The management of chronic pain is difficult for both patients and providers. The pathophysiologic mechanisms causing chronic pain differ greatly among patients, necessitating different treatment regimens. The mechanisms generating pain and the resultant sensitization of the nervous system are also unpredictable and variable, further complicating diagnosis and management. It also becomes difficult for the patient and provider to differentiate organic and emotional factors before initiating therapy.

Once the underlying cause of chronic pain is determined, the provider must evaluate for exacerbating factors.  It is important to assess for concomitant depression and anxiety, as these can worsen chronic pain.  It is also important to begin the treatment with planning and goal setting, so that the patient has realistic expectations.

The treatment options for chronic pain are broad.  Treatment must be individualized.  Opioids should not be the first line intervention.  As each patient requires individualized treatment based in their specific condition, this post cannot give specific recommendations on treatment.  Tricyclic antidepressants, especially nortriptyline and desipramine, are useful for the management of chronic pain, as they have dose-related analgesic properties. Antiseizure medications, such as gabapentin and pregabalin are useful for treatment of neuropathic pain.  Lidocaine patches are an option for very localized areas of pain. For some patients that experience pain that does not respond to more conservative measures, providers may consider spinal cord stimulation or intrathecal drug delivery systems in conjunction with a pain clinic referral.

Opioids are no longer recommended for primary treatment of chronic back pain.  Long-term opioids are often needed for patients with advanced metastatic cancer and for other patients with significant pain at the end of life.  Data shows that long-term use of opioids may actually worsen pain, a phenomenon called, opioid-induced hyperalgesia.  Tolerance also builds, necessitating progressively increased doses of drug, with also worsening side effects.  Due to the dramatic increase in overdose, the CDC has issued a checklist for prescribing opioids for chronic pain.

Transcranial magnetic stimulation (TMS) for chronic pain is currently being widely researched for use in chronic pain.  It has been approved for treatment of major depressive disorder unresponsive to first-line treatment. In this non-invasive treatment, a magnetic coil is placed near the head, which produces a localized electrical current.  Trials are currently ongoing.  Some studies have shown effectiveness for treatment of neuropathic pain.

Read more:

Harrison's Principles of Internal Medicine, 20e: Chapter 10: Pain: Pathophysiology and Management

Principles of Rehabilitation Medicine: Chapter 40: Neuropathic Pain