Morphine is the standard opioid analgesic for infantile pain that is moderate or severe. A loading dose is followed by a maintenance infusion. The key risk is that of respiratory depression, especially as clearance rates and plasma elimination half-life varies dramatically, not consistently approaching adult values until one month of age.
The synthetic opioid fentanyl is said to have a lower risk of hypotension, but vomiting may be more pronounced. Codeine has been reported to precipitate apnoea and severe hypotension - it should be avoided.
Intramuscular administration of opioids should be avoided as there is variable absorption.
Last reviewed 01/2018