Sydney: In what could disappoint many who pop paracetamol pills regularly for lower back pain, researchers have found that this common over-the-counter drug is not effective in the treatment of spinal pain and provides negligible benefits for osteoarthritis.

The study that “re-opened the debate on the effectiveness and safety of paracetamol” showed that for lower back pain, paracetamol had no effect and did not reduce disability or improve quality of life compared with the use of a placebo.

For osteoarthritis, they found small, but not clinically important benefits in the reduction of pain and disability compared with the use of a placebo, said a paper published in the British Medical Journal.

To reach this conclusion, lead author Gustavo Machado from the University of Sydney carried out a systematic review and meta-analysis to examine the efficacy and safety of paracetamol for lower back pain and osteoarthritis of the hip or knee.

The study included 13 randomised controlled studies that looked at the effects of paracetamol use compared with a placebo.

“Paracetamol use for osteoarthritis was also shown to increase the likelihood of having abnormal results on liver function tests by almost four times compared with a placebo, but the clinical relevance of this is still not certain,” the authors explained.

Nevertheless, the authors noted that “these results support the reconsideration of recommendations to use paracetamol for patients with low back pain and osteoarthritis of the hip or knee in clinical practice guidelines”.

They explained that if paracetamol is taken off existing guidelines, this will lead to an increase in the use of other prescribed drugs such as opioids and this will present new associated health problems.

Instead, they call for the use of safe and effective alternative treatments, especially non-drug options, such as exercise, which has clear benefits in the management of spinal pain and osteoarthritis.

Spinal pain, which includes neck and lower back pain, and osteoarthritis, the most common form of arthritis, are leading causes of disability worldwide.

Clinical guidelines recommend paracetamol as the first line drug treatment for both conditions.

“But the evidence to support this recommendation is weak and inconsistent and there are safety concerns with the recommended full dosage (up to 4000 mg/day)”, the study concluded.