Antidepressants prescribed for chronic pain sufferers ‘may not work’ | tech news
Hundreds of thousands of people in the UK are being prescribed antidepressants for chronic pain without sufficient evidence that they work, researchers said.
In the largest study of its kind, experts looked at drugs commonly prescribed in the NHS, including amitriptyline, duloxetine, fluoxetine (Prozac), citalopram, paroxetine (Seroxat) and sertraline.
Amitriptyline is one of the most commonly prescribed antidepressants for chronic pain in England. The NHS website says it can treat nerve pain and some back pain and prevent migraines.
But the new study, which included 176 studies and nearly 30,000 patients, concluded that only duloxetine had reliable evidence of pain relief.
Researchers, including from the Universities of Southampton, Bath, Bristol and University College London, also raised concerns about the lack of long-term safety data.
The National Institute for Health and Care Excellence (Nice) recommends a range of antidepressants as an option for chronic primary pain (where the underlying cause is unknown) and neuropathic pain such as neuralgia, some cancer pain, and conditions that can cause neuropathic pain such as z stroke, spinal cord injury and multiple sclerosis.
It told the PA news agency it had reviewed the new evidence but concluded it was “insufficient to justify an update of the recommendations in our chronic pain policy at this stage”.
But Professor Tamar Pincus, lead author of the new study from the University of Southampton, said: “This is a global public health problem.
“Chronic pain is a problem for millions who are prescribed antidepressants without adequate scientific evidence to show they help or understanding of the long-term health implications.
“Our review never found reliable evidence for the long-term effectiveness of antidepressants, and at no time found reliable evidence for their safety in chronic pain.
“Although we found that duloxetine provided short-term pain relief in the patients we studied, we remain concerned about its possible long-term harms given the gaps in the current evidence.”
Professor Pincus said that around a quarter to a third of people suffer from chronic pain.
She said the societal costs are “really, really high, both in terms of absenteeism from work, disability benefits, personal costs… and there’s very little we can do about it.”
She told reporters that while physical activity is known to help, many patients turn to medical professionals because they have trouble moving when the pain hits them hard.
She added that amitriptyline “has been on the market for ass years” and is “very, very cheap.”
“Because it’s been on the market for donkey years, it’s easy to get into the habit of prescribing it.
“It’s very likely that GPs will anecdotally see a response because placebo responses are incredibly high for chronic pain.
“One in three people responds to placebo. Is it safe? No it is not. Amitriptyline is certainly toxic in high doses. It has side effects that we know about.”
Professor Pincus said amitriptyline is “probably not very healthy” but added “we don’t know if it works”.
She added: “The fact that we can’t find evidence that it works or not is not the same as finding evidence that it doesn’t work.
“We don’t know — the studies just aren’t good enough, and we don’t know if it’s harmful or not.”
She said there were around 15 million low-dose prescriptions for amitriptyline in England in 2020-2021.
dr Hollie Birkinshaw, a researcher at the University of Southampton, said the clinical trials looked at three types of pain: fibromyalgia, nerve pain and musculoskeletal pain (mainly low back pain and osteoarthritis), with duloxetine and amitriptyline being among the most commonly studied antidepressants.
She said the researchers found the safety data for adverse events, serious adverse events and withdrawal to be “very poor,” adding, “Unfortunately, we cannot draw any reliable conclusions for antidepressant safety or adverse effects from our data.” ‘
dr Birkinshaw said the only “consistent picture” on effectiveness was for duloxetine but not other antidepressants used in the UK.
Statistician Gavin Stewart, co-author of the study from Newcastle University, said the team is now asking Nice and the US Food and Drug Administration to update their guidelines, “and to the funders who are supporting small and flawed studies set”.
The authors urged people not to stop their medication but to speak to a family doctor if they have concerns.
dr Ryan Patel of King’s College London said of the study: “If you’re someone living with chronic pain and taking antidepressants to treat your symptoms, it’s best to keep taking them if they’re working for you.
“The systems that regulate mood and pain overlap significantly, meaning some antidepressants may provide pain relief.
“What this comprehensive analysis shows is that if clinical trials are poorly designed with the assumption that everyone’s pain experience is the same, most antidepressants appear to have limited usefulness in treating chronic pain.”
A spokesman for Nice said: “Our chronic pain guidance, published in 2021, recommends that antidepressants for people aged 18 and over can be considered for the management of chronic primary pain, after a detailed discussion of the benefits and harms.
“This is because these drugs have been shown to help with quality of life, pain, sleep and psychological distress, even when no depression has been diagnosed.
“Nice conducted a careful and comprehensive review of the results and we concluded that the new evidence is insufficient to justify an update of the recommendations in our chronic pain guideline at this stage.”
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