Morphine Equivalent Calculation
This patient's total daily morphine equivalent dose (MME) is 30 MME/day from hydromorphone alone; the T3 (codeine/acetaminophen) contributes an additional 18 MME/day, for a combined total of 48 MME/day. 1
Calculation Breakdown
Hydromorphone Component
- Daily hydromorphone dose: 6 mg/day
- CDC conversion factor for hydromorphone: 5.0 1
- Calculation: 6 mg × 5.0 = 30 MME/day 1
Codeine Component (T3)
- T3 composition: Each tablet contains codeine 30 mg + acetaminophen 300 mg
- Daily codeine dose: 4 tablets × 30 mg = 120 mg/day
- CDC conversion factor for codeine: 0.15 1
- Calculation: 120 mg × 0.15 = 18 MME/day 1
Total MME
- Combined daily MME: 30 + 18 = 48 MME/day 1
Clinical Context and Risk Assessment
This patient's total opioid burden of 48 MME/day places them just below the 50 MME/day threshold where the CDC recommends pausing and carefully reassessing benefits versus risks before any further dose escalation. 1
Key Safety Considerations
- At dosages approaching 50 MME/day, patients experience progressive increases in overdose risk without necessarily experiencing proportional improvements in pain control or function 1
- Before increasing beyond 50 MME/day, clinicians should pause and carefully reassess individual benefits and risks, as many patients do not experience benefit from higher doses 1
- Any dosage increases should be by the smallest practical amount 1
Important Caveats About Conversion Factors
The 2022 CDC guideline updated the hydromorphone conversion factor from 4.0 (used in 2016) to 5.0, reflecting more recent evidence about hydromorphone's relative potency. 1
Critical Warnings
- These conversion factors are specifically for calculating MME for comparison purposes only and should never be used directly when switching patients between opioids 1
- When actually converting between opioids, the new opioid should be dosed substantially lower (typically 25-50% reduction) than the calculated MME to avoid overdose due to incomplete cross-tolerance 1, 2
- Equianalgesic conversions are estimates only and cannot account for individual variability in genetics and pharmacokinetics 1