Paracetamol no better than placebo for lower back pain: study

Paracetamol is no better than placebo at speeding recovery from acute episodes of lower back pain or improving quality of life, according to the first large randomised trial published in British medical journal The Lancet.

Low-back pain is the leading cause of disability worldwide.

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 robust evidence that it is effective in people with low-back pain.

In the new study, researchers from Sydney University randomly assigned 1,652 individuals with acute low-back pain from 235 primary care centres in Australia, to receive up to four weeks of paracetamol in regular doses (three times a day; equivalent to 3,990 mg per day), paracetamol as needed (maximum 4,000 mg per day), or placebo.

All participants received advice and reassurance and were followed-up for three months.

No differences in the number of days to recovery were found between the treatment groups -- median 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.

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

The authors of the paper believed that, their findings questioned the universal endorsement of paracetamol as the first choice painkiller for low-back pain, and suggested that more robust and consistent researches need to be done to confirm their findings.

They also pointed out that, understanding why paracetamol works for other pain states but not low-back pain would help direct future treatments.