Paracetamol for pain in adultsBMJ 2019; 367 doi: https://doi.org/10.1136/bmj.l6693 (Published 31 December 2019) Cite this as: BMJ 2019;367:l6693
- Bruno T Saragiotto, assistant professor1 2 3,
- Christina Abdel Shaheed, research fellow2 3,
- Chris G Maher, professor2 3
- 1Masters and Doctoral Programs in Physical Therapy, Universidade Cidade de São Paulo, São Paulo, Brazil
- 2Institute for Musculoskeletal Health, University of Sydney, Camperdown, New South Wales, Australia
- 3Faculty of Medicine and Health, School of Public Health, University of Sydney, New South Wales, Australia
- Correspondence to
What you need to know
A trial of paracetamol is reasonable in patients with mild or moderate acute pain from conditions such as migraine, headache, renal colic, and postpartum perineal pain
The evidence for using paracetamol to treat chronic pain is insufficient
Caution patients about possible adverse cardiovascular and gastrointestinal effects of paracetamol, the risk of overdose (>3 g/day), and adverse effects from long term use such as liver damage. Dose adjustment may be needed in frail older people and those weighing less than 50 kg
A 65 year old retired engineer has experienced a flare up in the pain he experiences with his osteoarthritic knee. While seeing his general practitioner (GP) about a skin lesion, he mentions the knee problem and asks if he should use paracetamol to manage the pain. The patient is overweight and physically inactive.
What is paracetamol?
Paracetamol (acetaminophen) is one of the most widely used over-the-counter drugs around the world for the treatment of pain.1 More than 100 different preparations, which contain paracetamol alone or in combination with other substances (eg, non-steroidal anti-inflammatory drugs or NSAIDs, caffeine, and tramadol) are available.2 Current understanding is that paracetamol acts by inhibiting the cyclooxygenase (COX) enzymes through metabolism of the peroxidase function of these isoenzymes. It is less certain if its action is mediated by inhibition of COX-1, COX-2, or COX-3 enzymes.234
Paracetamol is inexpensive in most countries and is generally considered safe. This contributes to its widespread use. Paracetamol is available in immediate release (short acting) and modified release (long acting) preparations. In December 2017, the European Medicines Agency recommended suspending the marketing of modified release paracetamol because of concerns about a rise in overdose events and ensuing complications,5 although the modified release preparations are still widely available in countries such as Australia, New Zealand, and the US. …