Should Antidepressants Be Used For Chronic Pain?

by Pooja Shete on Jan 24 2021 4:39 PM

Should Antidepressants Be Used For Chronic Pain?
For the treatment of pain, antidepressants are commonly used worldwide. However, a new research has shown that antidepressants offer little to no help for people suffering chronic back pain and osteoarthritis and they can even cause harm.
Millions of people globally are affected by back pain and knee osteoarthritis and they also are the leading cause of disability.

The first-line pain medications are paracetamol and ibuprofen. However, when these medications fail to improve the symptoms, physicians prescribe antidepressants for pain. Even though many clinical practice guidelines recommend the use of antidepressants for long term (chronic) back pain and hip and knee osteoarthritis, the evidence supporting their use is not certain.

The study conducted is published in the journal BMJ.

In order to help clinicians and patients make more informed decisions about whether to use antidepressants to treat chronic back pain and osteoarthritis pain, the study investigated the efficacy and safety of antidepressants by comparing it with placebo.

Lead author of the study, Dr Giovanni Ferreira, postdoctoral research fellow at the Institute for Musculoskeletal Health at the University of Sydney and Sydney Local Health District and the University's Faculty of Medicine and Health said, “The use of antidepressants to treat people with chronic back pain and osteoarthritis is increasing worldwide, but prior to our work, it was not clear whether antidepressants relieved pain or were safe. We conducted a review of all randomized clinical trials evaluating the efficacy of antidepressants for people with back pain or knee osteoarthritis and found that for back pain the antidepressants were either ineffective or provided a very small effect, which was unlikely to be perceived as worthwhile by most patients. For people with osteoarthritis, effects were still small, but could be potentially perceived as worthwhile by some patients.”

Antidepressants significantly increased the risk of adverse events. Although many people are being treated with these medications, no improvement in pain was seen and can increase harm.

The Study

For the study, a systemic review that involved 33 randomized controlled trials with more than 5,000 participants with low back or neck pain, sciatica, or hip or knee osteoarthritis. The trial evaluated six classes of antidepressants including tricyclic antidepressants (TCAs) and serotonin-noradrenaline reuptake inhibitors (SNRIs).

The scale for pain is between 0-100 which is a common threshold in studies of chronic pain. Most of the clinical trials included in the review did not consider patients with pain and depression, hence these results applied to patients for their pain condition, not depression in people living with pain.

Findings Of The Study

  • SNRIs had a insignificant small effect on the back pain. The effect was clinically not important
  • SNRIs in osteoarthritis pain had a slightly stronger effect after three months
  • Tricyclic antidepressants (TCAs) were not effective for reducing back pain and related disability
  • Tricyclic antidepressants (TCAs) and SNRIs can reduce pain in people with sciatica associated with back pain, however the evidence was not enough to draw any firm conclusions
  • Patients taking SNRI show an increased risk of adverse events such as nausea
The co-authors of the study advised that those currently taking antidepressants for treating back pain and osteoarthritis should not abruptly stop the treatment. They should consult with their doctor before stopping the treatment.

They added, "This can lead to withdrawal effects which can be distressing and sometimes present as serious health issues. These withdrawal effects include dizziness, nausea, anxiety, agitation, tremor, sweating, confusion and sleep disturbance."

Dr Ferreira added, "More research is needed to resolve uncertainties about the efficacy of antidepressants for sciatica and osteoarthritis highlighted by this review."