Opioid Conversion Guidelines

Introduction to Opioid Conversion

The equivalent dose of IV hydromorphone for 50 micrograms of IV fentanyl is approximately 0.8-1 mg, based on the equianalgesic ratio where fentanyl is approximately 60-100 times more potent than morphine, and morphine is approximately 5-7 times less potent than hydromorphone 1, 2

The National Comprehensive Cancer Network recommends determining the equianalgesic ratio between opioids, with an IV fentanyl to IV morphine ratio of approximately 100:1 and an IV morphine to IV hydromorphone ratio of approximately 5:1 1, 2, 3
The National Comprehensive Cancer Network suggests calculating the morphine equivalent dose, where 50 mcg IV fentanyl is equivalent to 5 mg IV morphine 2, 4
The National Comprehensive Cancer Network recommends converting to hydromorphone, where 5 mg IV morphine is equivalent to 1 mg IV hydromorphone 2, 4
Consider reducing the calculated dose by 25-50% to account for incomplete cross-tolerance, especially if pain was previously well-controlled, as suggested by the National Comprehensive Cancer Network 2, 3

Individual patient factors, such as age, renal function, and prior opioid exposure, may necessitate dose adjustments, according to the National Comprehensive Cancer Network and Intensive Care Medicine 2, 5
Careful titration based on patient response is essential after conversion, as recommended by Intensive Care Medicine and the National Comprehensive Cancer Network 2, 3, 5
Close monitoring for both pain control and side effects is required during the first 24 hours after conversion, as suggested by Intensive Care Medicine and the National Comprehensive Cancer Network 2, 3, 5
Provide rescue doses of short-acting opioids (10-20% of 24-hour dose) for breakthrough pain, as recommended by the National Comprehensive Cancer Network 2, 3
Avoid using morphine in patients with renal failure due to risk of accumulation of renally cleared metabolites; hydromorphone may be preferred in this population, according to the National Comprehensive Cancer Network 2, 3

Starting with too high a dose of hydromorphone can lead to respiratory depression, as warned by Intensive Care Medicine and the National Comprehensive Cancer Network 2, 5
Starting with too low a dose may result in inadequate pain control, as noted by the National Comprehensive Cancer Network 2, 3
Different opioid receptors may have varying degrees of tolerance, necessitating dose adjustments, as suggested by the National Comprehensive Cancer Network 2, 3
Patient response to opioids can vary significantly, requiring individualized titration, as recommended by Intensive Care Medicine and the National Comprehensive Cancer Network 2, 5