The content of this website is intended for healthcare professionals only

Paracetamol ineffective for lower back pain

Study suggests rethink on doctors recommending drug for back pain

Adrian O'Dowd

Thursday, 24 July 2014

Doctors should consider rethinking the standard policy of recommending paracetamol for lower back pain, according to a study* published today in The Lancet.

In a large trial, Australian researchers found that paracetamol was no better than placebo at speeding recovery from acute episodes of lower back pain or improving pain levels, function, sleep, or quality of life.

Low-back pain is a leading cause of disability worldwide and currently, national clinical guidelines universally recommend paracetamol as the first choice analgesic for acute low-back pain, despite the fact that no previous studies have provided clear evidence of its effectiveness.

In the study, described as the first large randomised trial to compare the effectiveness of paracetamol with placebo for low-back pain, researchers recruited 1,652 individuals (of an average age 45) who had with acute low-back pain from 235 primary care centres in Sydney, Australia.

The participants in the Paracetamol for Low-Back Pain Study (PACE), carried out between November 2009 and March 2013, were randomly assigned to receive up to four weeks of paracetamol in regular doses (three times a day), paracetamol as needed, or placebo.

After follow-up, the researchers found there were no differences in the number of days before recovery between the treatment groups. The average time to recovery was 17 days in the regular paracetamol group, 17 days in the as-needed paracetamol group, and 16 days in the placebo group.

The drug also had no effect on short-term pain levels, disability, function, sleep quality, or quality of life. Numbers of participants reporting adverse events was similar between the groups.

Lead author Dr Christopher Williams from the George Institute for Global Health at the University of Sydney, said: “Simple analgesics such as paracetamol might not be of primary importance in the management of acute lower back pain.

“The results suggest we need to reconsider the universal recommendation to provide paracetamol as a first-line treatment for low-back pain, although understanding why paracetamol works for other pain states but not low-back pain would help direct future treatments.

“In view of the quick timeframe in which participants in our trial improved compared with other cohorts, it would be interesting to see whether advice and reassurance (as provided in our trial) might be a more effective than pharmacological strategies for acute episodes of low-back pain.”

Writing in a linked comment**, Bart Koes and Wendy Enthoven from Erasmus MC, University Medical Center in Rotterdam, Netherlands said: “Although the findings from this high-quality trial are clear, the content of guidelines should not be changed on the basis of a single trial; more robust and consistent evidence, including verification of the results in other populations, is needed.”

* Williams C M, et al. Efficacy of paracetamol for acute low-back pain: a double-blind, randomised controlled trial. The Lancet, Early Online Publication, 24 July 2014. doi:10.1016/S0140-6736(14)60805-9

** Koes B W, Enthoven W T. Do patients with acute low-back pain need paracetamol? The Lancet, Early Online Publication, 24 July 2014. doi:10.1016/S0140-6736(14)60978-8

Registered in England and Wales. Reg No. 2530185. c/o Wilmington plc, 5th Floor, 10 Whitechapel High Street, London E1 8QS. Reg No. 30158470