The release of another large-scale study has confirmed what clinicians already know – that paracetamol is “not clinically effective” in treating osteoarthritis pain or improving physical function.
The Lancet study follows a systematic review and meta-analysis published in the BMJ last year that found little evidence that paracetamol worked for OA or lower back pain compared to placebo.
Dr Sam Whittle, senior consultant rheumatologist at South Australia’s Queen Elizabeth Hospital and senior lecturer at the University of Adelaide, said it appeared the latest study was further “confirmation of what we already know”.
He said it was clear that a blanket recommendation for the use of paracetamol to treat OA was “no longer a scientifically tenable recommendation.”
“It may still have a role but we shouldn’t be kidding ourselves that is has a major role because it doesn’t,” he said. “I’m not sure it (the latest findings) will come as a huge surprise to most people.”
The Lancet study released this week was a large-scale analysis of pain-relief medication for osteoarthritis and found that paracetamol did not meet the minimum standard of clinical effectiveness in reducing pain or improving physical function in patients with knee and hip osteoarthritis.
Although paracetamol was slightly better than placebo, the researchers concluded that paracetamol on its own has no role in the treatment of patients with osteoarthritis, irrespective of dose.
They found that the NSAID diclofenac 150mg/day provided the most effective short-term pain relief, however they cautioned against long-term NSAID use because of known side-effects.
Writing in a linked Comment in The Lancet, Professor Nicholas Moore and colleagues from the Department of Pharmacology at the University of Bordeaux, Bordeaux, France said it was remarkable to see that paracetamol does not seem to confer any demonstrable effect or benefit in osteoarthritis, at any dose, although he conceded it was not unexpected.
“Paracetamol has been on the market for as long as most of us remember,” he said.
“Its efficacy has never been properly established or quantified in chronic diseases, and is probably not as great as many would believe. Its safety is also questioned, not just in overdose.”
Dr Whittle said OA remained one of the last frontiers left in rheumatology, but he was hopeful that there would one day be an effective and safe long-term pharmacological treatment available. In the meantime, he said it was important not to abandon existing interventions.
This includes non-pharmacological therapies such as weight loss, exercise, education programs and surgery.
“These are effective and should be a front line treatment,” he told the limbic.
He said that while paracetamol was a “really really good” general analgesic, it clearly was not effective for OA pain and it was time to move on.
“I doubt that learning more and more will add anything else,” he said. “I think we should stop investigating the use of paracetamol for osteoarthritis, I think the jury’s in – it’s not effective for patients with osteoarthritis.”