2 August 2010

Codeine is a weak opioid used in many combination pain relief products, but its role in managing acute pain is questioned in this month’s edition of Australian Prescriber.

In the article Dr Bridin Murnion, from the Drug Health Service at Royal Prince Alfred Hospital Sydney, discusses the evidence around combinations of different painkillers in the same tablet (eg. ibuprofen or paracetamol with codeine). She argues that in many cases pain relief is not increased by using two different painkillers.

“Codeine is often an ingredient in combination painkillers, however there is not much evidence for its effectiveness and the role of codeine in managing acute pain is unclear,” says Dr Murnion.

NPS’s review of evidence shows that studies in acute pain suggest only modest additional pain relief is achieved when codeine is added to paracetamol, and the risk of side effects increases after repeated doses.

As an opioid, codeine can be addictive. When people take it in higher doses than recommended, they are also taking high doses of the other pain relief ingredients, paracetamol or ibuprofen, and it’s these ingredients which, when misused, can cause serious adverse events such as stomach and liver damage.

A National Health and Medical Research Council review found insufficient evidence to recommend the use of paracetamol/codeine combinations in acute low back pain, acute neck pain, acute shoulder pain or acute knee pain.

“For dental pain, the most effective approach is to undertake appropriate dental treatment. After dental extraction, anti-inflammatory medications are better than combinations of paracetamol and codeine,” Dr Murnion advises.

While there is a significant body of evidence identifying the efficacy of NSAIDs (e.g. ibuprofen, aspirin, diclofenac) in acute pain, there are limited data on combining them with opioids.

“Many anti-inflammatory drugs are more effective than combinations of codeine with paracetamol or aspirin,” she writes.

Dr Murnion says the recent rescheduling of these products is unlikely to impact significantly on people’s pain relief options but may reduce the harms from overuse.

Australian Prescriber is an independent peer-reviewed journal providing critical commentary on therapeutic topics for health professionals, particularly doctors in general practice. It is published by NPS, an independent, non-profit organisation for Quality Use of Medicines funded by the Australian Government Department of Health and Ageing.