This recent meta-analysis in the BMJ found that paracetamol (acetaminophen) was no better than placebo for the treatment of low back pain. Low back pain (LBP) is an increasingly common condition, for which patients often present to the ED. Treatment options are limited with NSAIDs and acetaminophen being two commonly prescribed medications for pain. This recent meta-analysis in the BMJ found that paracetamol (acetaminophen) was no better than placebo for low back pain. It included two trials including 1692 patients evaluated paracetamol on immediate pain reduction and found no difference compared to placebo (weighted mean difference 1.4, 95% CI -1.3 to 4.1). One trial (1652 patients) found no effect on pain (-0.5, -2.9-1.9), disability (0.4, -1.7-2.5), or quality of life measured on a 12-item survey. Patients received doses in the range of 3900-4000 mg/day and followed patients for up to 12 weeks.
The analysis also included ten trials, (3541 patients) which evaluated the efficacy of paracetamol on patients with osteoarthritis of the hip or knee. Here paracetamol provided significant but not clinically important reduction in pain. Although adverse events were similar in the paracetamol and placebo groups, patients receiving paracetamol were nearly four times more likely to have abnormal liver function test results (3.8, 1.9-7.4).