Opioid Dose Conversion for End-of-Life Care

Introduction to Opioid Conversion

The Centers for Disease Control and Prevention (CDC) recommends calculating the total daily oxycodone dose by multiplying the dose by the frequency of administration, for example, oxycodone 10 mg × 4 times daily = 40 mg/day total oxycodone 1
The CDC guidelines suggest a conversion factor of 1.5 for oxycodone to morphine, resulting in a 60 mg oral morphine equivalent daily dose for a patient taking 40 mg of oxycodone per day 1, 2

The National Comprehensive Cancer Network (NCCN) recommends calculating the appropriate liquid morphine dose by dividing the total daily oral morphine equivalent dose by the concentration of the liquid morphine, for example, 60 mg ÷ 20 mg/ml = 3 ml total daily dose 3
The NCCN suggests dividing the total daily dose into 4 doses, resulting in 0.75 ml (15 mg) every 6 hours, and then adjusting for end-of-life care and incomplete cross-tolerance by reducing the dose by approximately 25% 4, 5
The CDC recommends a final dose of 0.6 ml (12.5 mg) every 6 hours, which is equivalent to 2.5 ml (50 mg) per day, administered as 0.6 ml (12.5 mg) every 6 hours 2

The NCCN recommends more frequent assessment and titration for actively dying patients to ensure adequate pain control 4, 5
The NCCN suggests prescribing additional doses (approximately 10-20% of the 24-hour dose) for breakthrough pain 5, 6
The NCCN emphasizes the importance of clinical judgment in titrating to the desired response due to individual patient variability 4, 3
The CDC recommends closely monitoring for signs of respiratory depression, especially during the first 24-48 hours after conversion 1, 2

The NCCN recommends converting to subcutaneous or intravenous morphine at a 3:1 ratio (oral:parenteral) if the patient becomes unable to take oral medications 5, 6
The CDC warns against using the calculated morphine equivalent dose (MED) directly for conversion and recommends a reduction of 25-50% when switching between opioids due to incomplete cross-tolerance 1, 2
The NCCN emphasizes the importance of avoiding underdosing and being prepared to titrate upward if needed to ensure adequate pain control in actively dying patients 4, 5

The National Comprehensive Cancer Network recommends that for a patient taking oxycodone, the long-acting morphine equivalent can be calculated and administered as 135 mg every 12 hours of extended-release morphine, with a total daily dose of 270 mg oral morphine 7, 8
When rotating between opioids, the calculated equianalgesic dose should be reduced by 25-50% to account for incomplete cross-tolerance, according to the National Comprehensive Cancer Network 7, 8

If pain was well-controlled on oxycodone, the morphine dose should be reduced to 135-202.5 mg/day (50-75% of calculated dose), as recommended by the National Comprehensive Cancer Network 7, 8
If pain was poorly controlled, the National Comprehensive Cancer Network suggests using 100% of the calculated dose (270 mg/day) or even increasing by 25% 8

The National Comprehensive Cancer Network recommends prescribing immediate-release morphine at 10-20% of the 24-hour dose for breakthrough pain, which is approximately 27-54 mg per day 7, 9
The immediate-release morphine dose for breakthrough pain can be divided into individual rescue doses of approximately 5-10 mg every 2-4 hours as needed, according to the National Comprehensive Cancer Network 7, 9

The National Comprehensive Cancer Network advises avoiding morphine in patients with renal failure due to accumulation of renally cleared toxic metabolites 7, 8
The National Comprehensive Cancer Network recommends being prepared to titrate upward by 25-50% if pain control is inadequate after the initial conversion 8