The natural history of acute low back pain (aLBP) indicates that somewhere between 60-70% of episodes have spontaneously resolved by 3 weeks, and 80-90% by 3 months. We would hope that the goals of clinicians in their choice of pharmacotherapy and activities (physical therapy, exercise) are to shorten time to recovery, improve functional status during recovery, and provide symptom relief. A Cochrane Database analysis has confirmed the efficacy of NSAIDs for aLBP. What about acetaminophen? (Note: for readers who choose to review the original reference on this article, the word “paracetamol” is used in the original title, because that is the preferred term in the United Kingdom and Australia for what we call “acetaminophen” in the United States).

In this double-blind, placebo-controlled study conducted in Sydney, Australia, patients with aLBP (n = 1, 096) were randomized to treatment with pro re nata acetaminophen (up to 4000 mg/d) or placebo and followed for 3 months. The primary outcome was aLBP recovery, defined as a score of ≤ 1 on a 1-10 pain scale for at least 7 consecutive days.

No differences were found in time to recovery between groups. The authors suggest that although replication of their data with another clinical trial would make these conclusions more definitive, clinicians should be circumspect about use of acetaminophen in aLBP.