Doubt cast on efficacy of paracetamol for lower back pain
Paracetamol is no better than placebo at speeding recovery from acute episodes of lower back pain or improving related lifestyle factors, according to a large randomised trial.
The findings question the endorsement by international guidelines of paracetamol as the first choice painkiller for lower-back pain, said the study authors in The Lancet.
The Paracetamol for Low-Back Pain Study (PACE) involved 1,652 individuals with an average age of 45. They were randomised to receive up to four weeks of paracetamol three times a day (equivalent to 3,990mg per day), paracetamol as needed (up 4,000mg per day) or placebo.
“This study may cause us to reconsider the way we treat patients here with acute low back pain”
No differences in the number of days to recovery were found between the groups. Median time to recovery was 17 days in both the regular paracetamol and the as-needed groups, and 16 days for placebo.
Paracetamol also had no effect on short-term pain levels, disability, function, sleep quality, or quality of life.
“Simple analgesics such as paracetamol might not be of primary importance in the management of acute lower back pain”, said lead author Dr Christopher Williams, from the George Institute for Global Health at the University of Sydney in Australia.
“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,” he added.
The research, funded by the National Health and Medical Research Council of Australia and GlaxoSmithKline, was welcomed by other scientists who called for more research to be carried out.
Writing in The Lancet, Bart Koes and Wendy Enthoven from the Erasmus University Medical Centre in Rotterdam, 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.
“Furthermore, efforts to establish if prescription of other simple analgesics has additional benefit to advice and reassurance of the favourable prognosis for acute low-back pain are very welcome.”
Professor Sallie Lamb, director of the Oxford Clinical Trials Unit, said: “This study may cause us to reconsider the way we treat patients here with acute low back pain.”