Choosing an opioid 

When an individual’s pain is not being managed effectively by paracetamol (with or without an adjuvant), the World Health Organization (WHO) Analgesic Ladder suggests moving to an opioid from Step 2 or 3. The opioids within Steps 2 and 3 are described below.

Opioids come in different dose forms (oral/transdermal/transmucosal/injectable) and with different release characteristics (immediate release and modified release). Modified release (MR) preparations tend to be used to control background pain over a 24 hour period. Immediate release (IR) preparations can be prescribed and given ‘as required’ for breakthrough pain. Oral immediate release preparations act quickly, for example oral morphine will start to have an effect within 20-30 minutes with peak effect at approximately 60 minutes. Titration of the background modified release opioids is guided by how much immediate release opioids are required.

Refer to Pain management guideline.