Review finds no role for paracetamol on its own in treating osteoarthritis
March 23 2016
Paracetamol on its own has no role in treating patients with osteoarthritis irrespective of dose, a review of scientific literature has concluded. However, diclofenac 150mg/day was considered the most effective non-steroidal anti-inflammatory drug both in terms of improving pain and function.
The Lancet study included 74 randomised trials covering data from a total of 58,556 patients. It found evidence to support the effectiveness of diclofenac 150mg/day, etoricoxib 30mg/day, 60mg/day, and 90mg/day, and rofecoxib 25mg/day and 50mg/day. It also found that the best interventions were diclofenac 150 mg/day and etoricoxib 60mg/day.
The researchers also found that treatment effects increased as drug dose increased, but a liner dose effect was only significant for celecoxib, diclofenac and naproxen. They also found no evidence that treatment effects varied over the duration of the treatment.
Commenting on the findings, the OTC trade body, the Proprietary Association of Great Britain, noted that the study had found all preparations improved patients’ symptoms of pain compared to placebo.
John Smith, PAGB Chief Executive, commented: “Paracetamol has been on the market for more than 50 years and is a safe and effective treatment for mild to moderate pain relief. NICE guidelines recommend paracetamol as a first line pain relief drug for osteoarthritis.
“It is important to note that the authors of this study identified limitations in the quality of analysis, due to the data available. It is unclear whether investigators in some trials were properly blinded and most trials had a high risk of incomplete outcome data bias, therefore further research is needed to draw any firm conclusions.
“We would advise anyone who is concerned about the use of paracetamol to speak to their pharmacist in the first instance. Pharmacists are highly trained healthcare professionals and can provide useful information and advice on over-the-counter painkillers.”
The Royal College of General Practitioners said the research added to the evidence around whether paracetamol was effective in osteoarthritis. Dr Maureen Baker, RCGP Chair, said: “The majority of evidence still suggests that paracetamol is a safe drug for most patients, but a number of recent studies – today’s included - do cast doubt on its effectiveness at treating osteoarthritis.
“What the study doesn’t suggest is a suitable – and safe – alternative for pain management in patients with osteoarthritis. We know that alternatives, such as NSAIDs, can be effective but they can have nasty side-effects for patients if they are taken over a long period of time. And whilst GPs understand and advocate lifestyle changes to patients, that can help ease their pain, there is a limit to how viable these are, particularly in serious cases.”
Dr Baker added that it was important that as new research is published, it is taken on board as guidelines for healthcare professionals are updated.
BR da Cosat et al. ‘Effectiveness of non-steroidal anti-inflammatory drugs for the treatment of pain in knee and hip osteoarthritis: a network meta-analysis’. Lancet 2016. Published online March 17 2016