From the Research
The conversion ratio for IV to PO hydromorphone is approximately 1:2.5, meaning that 1 mg of IV hydromorphone is equivalent to about 2.5 mg of oral hydromorphone. When converting a patient from IV to oral hydromorphone, multiply the IV dose by 2.5 to determine the appropriate oral dose. For example, if a patient is receiving 2 mg of IV hydromorphone, the equivalent oral dose would be approximately 5 mg. This conversion ratio accounts for the difference in bioavailability between the two routes of administration, as found in a study published in the Journal of Pain and Symptom Management 1.
The study, which analyzed data from 4745 consecutive inpatient palliative care consults, determined that the median conversion ratio from IV to PO hydromorphone was 2.5, with a strong correlation between the two routes of administration. The findings of this study provide a reliable basis for converting IV hydromorphone to oral hydromorphone in clinical practice.
Some key points to consider when making this conversion include:
- Starting with a conservative dose and titrating as needed based on the patient's pain control and side effects
- Considering the difference in onset of action between IV and oral hydromorphone, which may necessitate adjustments in dosing frequency
- Being aware of the potential for individual variability in response to hydromorphone, and monitoring patients closely for signs of overdose or underdose.
It's also important to note that other studies, such as those published in 1997 2, 2006 3, 2009 4, and 2021 5, may provide additional information on the use of hydromorphone in different clinical contexts, but the study published in 2017 1 provides the most relevant and reliable guidance on the conversion ratio for IV to PO hydromorphone.