Co-codamol 30/500 (Post-Operative Step-Down Analgesia)

How it works

Paracetamol produces central analgesia and antipyresis through poorly understood central mechanisms, while codeine is a prodrug metabolised to morphine that acts on mu-opioid receptors.

Prescribing in practice

• Codeine metabolism via CYP2D6 is highly variable, so ultra-rapid metabolisers risk morphine toxicity and poor metabolisers gain little analgesia; it is contraindicated in breastfeeding mothers and in children after tonsillectomy or adenoidectomy for obstructive sleep apnoea.
• Account for all paracetamol-containing products to avoid exceeding the maximum daily paracetamol intake and causing hepatotoxicity.
• As an opioid it can cause constipation, sedation and respiratory depression, so co-prescribe a laxative and review duration to limit dependence.

Monitoring

Monitor pain scores, sedation, bowel function and respiratory rate, and review the ongoing need for opioid analgesia regularly.

Counselling the patient

• Do not take other paracetamol-containing medicines at the same time.
• It may cause drowsiness and constipation; avoid alcohol and seek advice if breathing feels affected.

Evidence & guidelines

Combination paracetamol-opioid analgesia is supported by NICE postoperative pain guidance and systematic reviews of acute pain management.