Study questions use of paracetamol for lower back pain and osteoarthritis

Paracetamol is ineffective in reducing pain, disability or improving quality of life for patients who suffer from low back pain or osteoarthritis of the hip or knee, and its use may affect the liver, according to a study published BMJ.

The study provides new evidence that paracetamol is no better at treating low back pain than a placebo and its effect on osteoarthritis of the hip or knee is too small to be clinically worthwhile.

Paracetamol is currently recommended by most international clinical guidelines as a first line treatment for low back pain and osteoarthritis.

Related:Paracetamol: Is it as safe as we thought?

MachadoLead author Gustavo Machado, PhD, of The George Institute and the University of Sydney, Australia, and colleagues, conducted a systematic review with meta-analysis and included 13 randomized trials including more than 5,300 patients with low back pain and hip/knee osteoarthritis.

“Paracetamol is not effective for patients with low back pain in reducing pain and disability or improving quality of life, and only offers minimal and not clinically important benefits for patients with osteoarthritis of the hip or knee,” according to Machado. 

Related:Most medications found better than Tylenol for knee pain

Low back pain is the leading cause of disability worldwide, and osteoarthritis of the hip or knee is the 11th highest contributor to global disability. In Australia, back pain and osteoarthritis account for $8.4 billion in healthcare costs per year. Increasing evidence examining early medical imaging for low back pain, which can cost up to $220 million a year in Australia, shows that this procedure isn’t always necessary.

“Clinical guidelines of back pain and osteoarthritis often recommend paracetamol as the first line analgesic medication,” Machado said. “Our results suggest that these clinical guidelines should be reviewed. 

“Paracetamol is ineffective for patients with low back pain and brings negligible benefits for patients with osteoarthritis. We call for a review of clinical guidelines recommending this medication as first-line care.”

Marchado and colleagues also investigated the safety of paracetamol and found that it is associated with potential abnormal results on liver function tests.

“Nearly 7% of patients taking paracetamol presented abnormal results on liver function tests compared to 2% of patients taking placebo pills,” he said.

Other treatments known to be effective for patients with low back pain include advice and education programs, physical therapies such as spinal manipulation and exercise as well as psychological therapies such as cognitive behavioral therapy. Land or water-based aerobic exercise, strengthening exercise, weight management and oral or topical anti-inflammatory medicines have been shown to provide benefit for patients with lower limb osteoarthritis.

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