Oxycodone with naloxone

How it works

Oxycodone provides analgesia through mu opioid receptor agonism, while orally administered naloxone acts locally in the gut to block intestinal opioid receptors yet undergoes extensive first-pass metabolism, so it counteracts opioid-induced constipation without reducing systemic analgesia.

Prescribing in practice

• As with all strong opioids, the principal hazard is respiratory depression, with risks of sedation, dependence and overdose, particularly when combined with other CNS depressants.
• The naloxone component relies on hepatic first-pass metabolism, so the combination should be avoided in moderate to severe hepatic impairment where naloxone may reach the circulation and reduce analgesia or precipitate withdrawal.
• Tablets must be swallowed whole; crushing or chewing the modified-release formulation can lead to rapid opioid release and dangerous overdose.

Monitoring

Monitor pain control, bowel function, sedation and respiratory status, and review regularly for signs of tolerance, dependence or misuse.

Counselling the patient

• Swallow the tablets whole—never crush, break or chew them—to avoid a dangerous opioid surge.
• Do not drink alcohol; report excessive drowsiness or slow breathing, and do not stop suddenly after regular use.

Evidence & guidelines

The oxycodone–naloxone combination is licensed for severe pain with the aim of reducing opioid-induced constipation, with prescribing guided by the SPC and opioid safety guidance.