Antidepressants are commonly prescribed to treat chronic pain, and prescribing is on the rise, but a recent University of Sydney led review has found most antidepressants are ineffective or treating chronic pain.
Published in The BMJ, the study reviewed the safety and effectiveness of antidepressants in the treatment of chronic pain.
Dr Giovanni Ferreria, from Sydney Musculoskeletal Health, University of Sydney, the lead author of the study said:
“This review, for the first time, brings together all the existing evidence about the effectiveness of antidepressants to treat chronic pain in one comprehensive document,”
The review looked at 26 systematic reviews between 2012 and 2022 and involved over 25,000 participants. The data included 22 pain conditions, including back pain, fibromyalgia, headaches, postoperative pain, and irritable bowel syndrome and examined eight antidepressant classes.
Tricyclic antidepressants
Tricyclic antidepressants, such as amitriptyline, are the most commonly used class of antidepressant to treat chronic pain in clinical practice, but the review showed there was little evidence to show they work well, or even at all, for most chronic pain conditions.
The research also showed there was no evidence, or inconclusive evidence, that fluoxetine, venlafaxine, mirtazapine were effective for a range of conditions such as irritable bowel syndrome, functional dyspepsia, fibromyalgia and phantom limb pain. This is despite them being commonly prescribed in general practice.
SNRI antidepressants
However, serotonin-norepinephrine reuptake inhibitors (SNRIs) such as duloxetine (cymbalta)did show some effectiveness for a number of pain conditions, including back pain, knee osteoarthritis, postoperative pain, fibromyalgia and neuropathic (nerve) pain.
Dr Ferreira said a more nuanced approach to prescribing antidepressants for pain is needed.
“Recommending a list of antidepressants without careful consideration of the evidence for each of those antidepressants for different pain conditions may mislead clinicians and patients into thinking that all antidepressants have the same effectiveness for pain conditions. We showed that is not the case.”
Co-author of this study is Dr Christina Abdel Shaheed clearly did not expect this outcome and is minimising these data. We have caught her misrepresenting her own data previously, and spouting anti-opioid rhetoric that her own research did not support.
She told the newsGP, that “that just because there is not enough evidence for some antidepressants’ efficacy in pain it does not mean they are useless.”
She said:
‘“Evidence of no benefit” is a very different proposition to “no evidence of benefit”,’ she said.
The irony being that this is almost exactly what people (like her) said about opioids in the past; “there is no evidence opioids work long term for pain.”
Now she is using the same argument about anti-depressants, but for the opposite effect. These people twist the ‘evidence’ to suit their own bias, with little to no regard of the consequences for people living with severe, daily pain. I, once again, call into question Dr Shaheed’s ethics as a researcher, not to mention as a human being.
She stated further:
‘This review found a surprising paucity of evidence in the field, warranting more research given the increase in prescribing of antidepressants for chronic pain globally.’
At least on this we can agree. There needs to be much more research, and that research needs to be reported on accurately.
In Australia, antidepressants prescribed for chronic pain are mostly off-label, meaning they are prescribed for a purpose for which the medication has not been approved. This is common practice in many realms of medicine. However, the only antidepressant that IS approved for treating pain in Australia is duloxetine, which is approved for diabetic neuropathic pain only. Yet you would be hard pressed to find a person living with chronic pain who has not at least been offered an antidepressant for pain. Some people are even pressured into taking antidepressants, despite not wanting to.
Much worse, many people living with severe chronic pain have had their opioids force-tapered and have been prescribed amitriptyline instead, because GPs are of the mistaken belief that amitriptyline is effective for chronic pain. Amitriptyline is not approved for treating any pain conditions in Australia, yet people are prescribed it daily.
This study clearly shows that amitriptyline (or any other antidepressant) is NOT effective for chronic pain and is in no way a substitute for opioids.
Currently, no data from Australia shows how many antidepressant prescriptions are for pain, these records are not kept. But this study shows that automatic prescribing of antidepressants for chronic pain needs to stop, as does the practice of force tapering opioids and replacing them with antidepressants.
More studies on Antidepressants for chronic pain
