NICU IV fentaNYL to PO morphine Calculator – IWK Drug Information Resource

This calculator is intended only for neonates receiving IV fentanyl for more than 10 days and provides a rough estimate for converting IV fentanyl to oral morphine. There is significant individual response to various opioids as well as unpredictable or incomplete cross tolerance between opioids; clinical judgement must always be used when converting opioids. Neonates can be more susceptible to adverse effects of opioids therefore consider starting at a lower dose than what the conversion suggests.

NOTE: It is not appropriate to use this calculator when converting from oral morphine to IV fentanyl as it tends to overestimate fentanyl requirements. In this situation, please use standard opioid equianalgesic tables combined with clinical judgement. Refer to Withdrawal Guidelines for further conversion information.

Current Rate of IV fentaNYL *

micrograms/kg/hour

Dosing Frequency for PO morphine *

Patient Weight (Use Weight on Pump) *

Reset

Please note: the calculated PO morphine dosing is an approximate conversion; consider a decrease or increase in recommended dose depending on the patient’s clinical status.

Consider the following prior to implementation:

Does the dose calculated make sense? How does it compare to the Neonatal and/or Pediatric morphine drug dosing guideline?
If concerned about treating pain in addition to withdrawal, a higher dose may be needed. If withdrawal is the only concern, consider starting at a lower dose.
Consider ordering a PO morphine breakthrough dose (one half of the calculated maintenance dose)