What is the oral (PO) morphine equivalent of 12 milligrams of intravenous (IV) Dilaudid (hydromorphone)?

From the Guidelines

To convert 12mg IV hydromorphone (Dilaudid) to oral morphine, the equivalent dose would be approximately 180mg of oral morphine. This conversion is based on the relative potency of these opioids, where IV hydromorphone is about 7.5 times more potent than oral hydromorphone, and oral hydromorphone is 7.5 times more potent than oral morphine, as shown in the study by 1. The calculation involves first understanding the relative effectiveness compared with oral morphine, as outlined in the table from the study by 1. Given that IV hydromorphone is not directly compared to oral morphine in the provided table, we must consider the potency ratios provided:

• IV morphine is 3 times more potent than oral morphine,
• Oral hydromorphone is 7.5 times more potent than oral morphine. However, since the direct conversion from IV hydromorphone to oral morphine isn't explicitly provided, we rely on the principle that IV hydromorphone's potency relative to oral morphine can be inferred from its known potency relative to other opioids and the general understanding of opioid conversion factors. The example calculation provided in the guidance suggests a stepwise conversion, but given the information from 1, a more straightforward approach considers the relative potencies directly. Thus, if 1mg of oral hydromorphone is equivalent to about 7.5mg of oral morphine, and considering the general principle that IV administration is more potent than oral, the conversion factor from IV hydromorphone to oral morphine would reflect both the IV to oral conversion and the hydromorphone to morphine conversion. Given the complexities and variations in opioid conversion, starting with a slightly lower dose (about 25-50% reduction) is prudent to account for incomplete cross-tolerance, so consider starting with 120-135mg of oral morphine and titrating as needed, as this approach prioritizes patient safety and manages the risk of overdose or adverse effects. Monitoring the patient closely for signs of oversedation or respiratory depression during this transition is crucial, especially when transitioning from a potent opioid like IV hydromorphone to oral morphine, as the risk of respiratory depression is a significant concern with opioid therapy, as noted in general clinical practice guidelines 1.

From the Research

Opioid Conversion Ratios

To determine the oral (PO) morphine equivalent of 12 milligrams of intravenous (IV) Dilaudid (hydromorphone), we need to consider the conversion ratios between different opioids.

• The conversion ratio from IV hydromorphone to oral morphine equivalent daily dose (MEDD) was found to be around 1:11.46 in a study published in the Journal of Pain and Symptom Management 2.
• This means that 1 mg of IV hydromorphone is equivalent to approximately 11.46 mg of oral morphine.
• Using this conversion ratio, we can calculate the oral morphine equivalent of 12 mg of IV hydromorphone: 12 mg x 11.46 = 137.52 mg.
• However, it's essential to note that there may be variations in conversion ratios depending on individual patient factors and the specific opioid being used.

Variations in Conversion Ratios

• A survey of palliative care professionals found significant variations in median conversion ratios from IV to oral morphine and from IV hydromorphone to oral morphine equivalent daily dose (MEDD) across different groups 3.
• Another study found that the conversion ratio from IV hydromorphone to oral hydromorphone was around 1:2.5, and the opioid rotation ratio from IV hydromorphone to MEDD was around 1:11.46 2.
• These variations highlight the importance of careful consideration and individualized calculation of opioid conversion ratios to ensure safe and effective pain management.

Clinical Implications

• When converting between different opioids, it's crucial to consider the specific conversion ratios and individual patient factors to avoid overdosing or underdosing.
• The use of standardized conversion tables and guidelines, such as those developed in the study published in the Journal of Education & Teaching in Emergency Medicine 4, can help improve the accuracy and safety of opioid conversions.
• Further research is needed to standardize opioid conversion ratios and ensure consistent practice among healthcare professionals.