What is the morphine (opioid analgesic) equivalent dose of 25 milligrams (mg) of hydromorphone (potent opioid analgesic)?

Morphine Equivalent of 25 mg Hydromorphone

25 mg of hydromorphone is equivalent to 125 mg of morphine milligram equivalents (MME), based on the CDC conversion factor of 5.0 for hydromorphone. 1

Conversion Calculation

The calculation is straightforward using the established conversion factors:

• According to the 2022 CDC Clinical Practice Guideline for Prescribing Opioids for Pain, hydromorphone has a conversion factor of 5.0 1
• Therefore: 25 mg hydromorphone × 5.0 = 125 MME

Important Considerations for Clinical Application

Potency Variations by Route of Administration

• The conversion factor of 5.0 applies to oral hydromorphone to oral morphine
• For intravenous (IV) hydromorphone:
  • IV hydromorphone is approximately 8.5 times as potent as IV morphine 2
  • The conversion ratio from IV to oral hydromorphone is approximately 1:2.5 3

Dose Adjustments for Clinical Scenarios

• When converting between opioids for ongoing therapy, dose reductions of 25-50% are recommended due to incomplete cross-tolerance 4
• For high-dose opioid therapy, standard conversion ratios may overestimate requirements:
  • Patients receiving ≥30 mg/day of IV hydromorphone may require a lower opioid rotation ratio (9.86) compared to those receiving <30 mg/day (11.54) 3
  • In some cases of high-dose hydromorphone therapy, patients may only require 20-25% of the calculated equivalent morphine dose 5

Clinical Pitfalls to Avoid

• Using fixed conversion ratios without considering patient factors can lead to under or overdosing 4
• Equianalgesic dose conversions are only estimates and cannot account for individual variability in genetics and pharmacokinetics 1
• When converting between opioids, the new opioid should typically be dosed lower than the calculated MME dose to avoid overdose due to incomplete cross-tolerance 1

Special Cautions

• For elderly patients or those with renal/hepatic impairment, consider using the lower end of the dosing range and reducing calculated doses by 25-50% 4
• Monitoring for side effects is critical when initiating or changing opioid therapy, particularly for respiratory depression with higher MME doses 4

Remember that while 25 mg of hydromorphone equals 125 MME, this conversion is meant as a guideline for understanding relative potency, not as an exact prescription for clinical conversion between medications.