Opioid Conversion Guidelines

Introduction to Opioid Conversion

The Centers for Disease Control and Prevention (CDC) recommends converting each medication to morphine milligram equivalents (MME) to determine the hydromorphone equivalent, with a conversion factor of 2.4 for fentanyl and 1.5 for oxycodone 1, 2
The National Comprehensive Cancer Network (NCCN) suggests adding the total MME and then converting to hydromorphone, using a conversion factor of 5.0 or 4.0 for hydromorphone 3

To calculate the MME for fentanyl, the maximum possible daily dose is 300 mcg, which is then converted to MME using a conversion factor of 2.4, resulting in 720 MME/day 1, 3
To calculate the MME for oxycodone, the maximum possible daily dose is 40 mg, which is then converted to MME using a conversion factor of 1.5, resulting in 60 MME/day 3, 4
The total MME is calculated by adding the MME of fentanyl and oxycodone, resulting in 780 MME/day 1

The total MME is then converted to hydromorphone using a conversion factor of 5.0, resulting in an oral hydromorphone equivalent of 156 mg/day, or using a conversion factor of 4.0, resulting in an oral hydromorphone equivalent of 195 mg/day 1, 5, 6
The Centers for Disease Control and Prevention (CDC) recommends a conversion ratio of 5:1 from oral to IV hydromorphone, meaning the IV dose would be about 1/5 of the oral dose 3

The NCCN recommends reducing the calculated hydromorphone dose by 25-50% to account for incomplete cross-tolerance and individual variability in pharmacokinetics 3, 4, 7
The CDC recommends starting with a lower dose of hydromorphone and titrating up as needed to avoid overdose, and monitoring closely for signs of respiratory depression or oversedation 1, 2
The NCCN suggests that equianalgesic dose conversions are only estimates and cannot account for individual variability in genetics and pharmacokinetics 1, 2

A more conservative approach would be to start with a much lower dose of hydromorphone (4-5 mg oral per day or 0.8-1 mg IV per day) and titrate based on patient response and pain control 3, 4
The CDC recommends monitoring closely for signs of respiratory depression or oversedation 1, 2

The CDC recommends not using calculated MME directly for conversion but rather as a guide, and accounting for PRN usage and patient-specific factors such as age, renal/hepatic function, and prior opioid exposure 1, 2, 3, 4
The NCCN suggests that inadequate monitoring is a common pitfall, and close monitoring is essential after any opioid conversion to ensure adequate pain control and avoid adverse effects 3, 4