Why use antidepressants to treat pain? The nation’s focus on the ongoing opioid epidemic and stricter guidelines on opioid prescribing has led to an increased utilization of non-opioid pain treatments in workers’ compensation. In a previous blog post, we looked at the use of anticonvulsants to treat pain because of their ability to create effective pain relief without the cravings, tolerance, or addiction issues that are typically associated with narcotics. Another therapeutic class commonly used to treat chronic pain is antidepressants, which may even be prescribed when depression is not a diagnosed condition for the injured worker.
Examples of antidepressants that are used to treat pain are tricyclic antidepressants (i.e., amitriptyline, imipramine, doxepin) and serotonin and norepinephrine reuptake inhibitors (SNRIs) (i.e., duloxetine, venlafaxine). These can provide effective analgesia in pain conditions such as neuropathic pain, musculoskeletal pain, and fibromyalgia. The pharmacological mechanism of these medications is not fully understood but is believed to work through the increase of neurotransmitters in the spinal cord that may reduce the conduction of pain signals to the brain.
The use of antidepressants in the treatment of certain types of pain can have a great impact in reducing the use, and thereby the risks, associated with opioids. It must be acknowledged that antidepressants do not work immediately to alleviate pain and most patients experience only moderate pain relief. However, antidepressant medications may be used safely in conjunction with other drug classes with faster onset of pain relief, such as non-steroidal anti-inflammatory drugs (NSAIDs).
The Food and Drug Administration (FDA) had approved the use of duloxetine, a serotonin and norepinephrine reuptake inhibitor (SNRI), specifically for fibromyalgia and chronic musculoskeletal pain based on studies for effectiveness and safety. “Off-label” prescribing constitutes the majority of antidepressant drug utilization in workers’ compensation. Expert guidelines in our industry, such as the Official Disability Guidelines (ODG) and American College of Occupational and Environmental Medicine (ACOEM), support the use of tricyclic antidepressants (TCAs) and SNRIs for neuropathic pain. If you see the use of antidepressants for chronic pain, remember that on a case-by-case basis, they may be appropriate.