Opioids with no role in pain management

Codeine, dextropropoxyphene and pethidine have no role in pain management because their use is associated with more harm than benefit.

There is no good evidence that codeine is more effective than paracetamol or nonsteroidal anti-inflammatory drugs (NSAIDs), or improves analgesia when combined with paracetamol or an NSAID. Codeine is converted to morphine via cytochrome P450 2D6 isoenzyme—rapid metabolisers may experience morphine-related adverse effects; poor metabolisers may have inadequate analgesia. The safety of codeine has been questioned and, following many reports of abuse with codeine-containing preparations, codeine has been rescheduled to a prescription-only medicine.

There is no evidence to suggest that dextropropoxyphene is more effective than paracetamol for pain management, but there is good evidence that dextropropoxyphene causes harm (eg fatal QT-interval prolongation).

There is no evidence to support that pethidine is more effective than other opioids. Pethidine is associated with significant toxicity due to metabolite accumulation; signs of toxicity include anxiety, mood change, tremors, twitching, myoclonic jerks and convulsions.