What is the morphine equivalent dose of Dilaudid (hydromorphone)?

Morphine Equivalent Dose of Dilaudid (Hydromorphone)

Dilaudid (hydromorphone) has a potency ratio of 5:1 compared to morphine when given intravenously, meaning 1 mg of IV hydromorphone is equivalent to approximately 5 mg of IV morphine. 1

Route-Specific Conversion Ratios

Intravenous (IV) Route

• 1 mg IV hydromorphone = 5 mg IV morphine 1
• This is clearly demonstrated in the case example from the NCCN guidelines where 10 mg IV morphine equals 2 mg IV hydromorphone 1

Oral (PO) Route

• 1 mg oral hydromorphone = 4-5 mg oral morphine 1, 2
• The FDA label confirms that 5 mg and 10 mg of oral hydromorphone are comparable to 30 mg and 60 mg of oral morphine respectively 2

Route Conversion (IV to PO)

• IV to oral hydromorphone conversion ratio is approximately 1:2.5 3
• This means 1 mg IV hydromorphone ≈ 2.5 mg oral hydromorphone

Clinical Application

When converting between morphine and hydromorphone:

1. Determine total 24-hour dose of the current opioid
2. Calculate equianalgesic dose using the appropriate conversion ratio:
   • IV morphine to IV hydromorphone: 5:1 ratio
   • Oral morphine to oral hydromorphone: 5:1 ratio
3. Reduce calculated dose by 25-50% to account for incomplete cross-tolerance 1
   • This is particularly important when switching between different opioids
   • Exception: If pain is poorly controlled, you may use 100% of the calculated dose

Example Calculation

For a patient taking 60 mg oral morphine daily:

• Step 1: 60 mg oral morphine ÷ 5 = 12 mg oral hydromorphone (equianalgesic dose)
• Step 2: Apply 25-50% reduction: 12 mg × 0.75 = 9 mg oral hydromorphone daily (25% reduction)
• Step 3: Divide into appropriate dosing schedule (e.g., 3 mg TID)

Important Considerations

• Higher doses may require different ratios: At higher doses (≥30 mg/day IV hydromorphone), a slightly lower conversion ratio to morphine may be needed 3
• Individual variability: Patient response to opioids varies significantly 1
• Monitor closely: After conversion, assess pain control and side effects frequently
• Breakthrough pain: Provide rescue medication (typically 10-15% of 24-hour dose)
• Incomplete cross-tolerance: The 25-50% dose reduction is critical to prevent overdosing when switching between different opioids 1

Common Pitfalls to Avoid

1. Failing to distinguish between routes: IV and oral conversion ratios are different
2. Omitting the cross-tolerance reduction: Can lead to excessive sedation or respiratory depression
3. Confusing the direction of conversion: Converting morphine to hydromorphone vs. hydromorphone to morphine requires different calculations
4. Not individualizing based on clinical response: Titrate as needed after initial conversion

Remember that these conversion ratios are guidelines and clinical judgment is essential when managing pain with potent opioids.