From the Guidelines
To convert IV hydromorphone to IV morphine, use a potency ratio of approximately 1:5, meaning 1 mg of IV hydromorphone is equivalent to about 5 mg of IV morphine. This conversion ratio is based on the most recent evidence from the CDC clinical practice guideline for prescribing opioids for pain - United States, 2022 1. When making this conversion, it's essential to start with the lower end of the conversion range and titrate as needed based on the patient's pain response and side effects.
Key Considerations
- The potency ratio of 1:5 is an estimate and may vary depending on individual patient factors, such as genetics and pharmacokinetics 1.
- Hydromorphone has a shorter duration of action (2-3 hours) compared to morphine (3-4 hours), so dosing frequency may need adjustment 1.
- It's crucial to monitor the patient closely after conversion, assessing their pain level, respiratory status, and sedation to ensure safety and efficacy of the new regimen.
Conversion Steps
- Determine the total amount of current IV hydromorphone in a 24-hour period.
- Calculate the equianalgesic dose of IV morphine using the potency ratio of 1:5.
- Start with the lower end of the conversion range and titrate as needed based on the patient's response.
Evidence Summary
The CDC clinical practice guideline for prescribing opioids for pain - United States, 2022 1 provides the most recent and highest-quality evidence for converting IV hydromorphone to IV morphine. This guideline recommends using a potency ratio of 1:5, which is consistent with other studies, such as the clinical practice guidelines for the management of pain, agitation, and delirium in adult patients in the intensive care unit 1. However, it's essential to note that individual responses to opioids can vary significantly, and close monitoring is necessary to ensure safe and effective pain management.
From the FDA Drug Label
The FDA drug label does not answer the question.
From the Research
Conversion from IV Hydromorphone to IV Morphine
- The conversion ratio from IV hydromorphone to IV morphine is not directly stated in the provided studies.
- However, study 2 found that 1 mg of IV hydromorphone is equivalent to 11.46 mg of oral morphine equivalent daily dose (MEDD).
- Study 3 reported a wide variation in opioid rotation ratios (ORRs) and conversion ratios (CRs) among palliative care clinicians worldwide, including a median ORR from IV hydromorphone to oral morphine of 10-20.
- Study 4 used an 8:1 conversion ratio from oral morphine to oral extended-release hydromorphone hydrochloride, but this is not directly applicable to the conversion from IV hydromorphone to IV morphine.
Limitations and Variations
- The studies provided do not offer a direct conversion ratio from IV hydromorphone to IV morphine, highlighting the need for further research to standardize practice 3.
- The conversion ratios and opioid rotation ratios vary widely among clinicians and studies, emphasizing the importance of individualized patient care and careful consideration of opioid conversions 2, 3, 4.
- The lack of consensus on conversion ratios and opioid rotation ratios may lead to poorly controlled pain or overdosing in patients, underscoring the need for caution and careful monitoring when converting opioids 2, 5.