Medications Stronger Than Hydromorphone (Dilaudid)
Fentanyl is significantly stronger than hydromorphone (Dilaudid), with a potency approximately 100 times greater than morphine, while hydromorphone is only about 7.5 times more potent than oral morphine. 1, 2
Comparative Opioid Potencies
Fentanyl
- Fentanyl is the most potent commonly used opioid in clinical practice, being 100 times more potent than morphine 1, 2
- Has faster onset of action compared to other opioids due to high lipophilicity (octanol:water partition coefficient >700) 2
- Available in multiple formulations including:
- Intravenous (fastest onset)
- Transmucosal (onset within 5 minutes)
- Intranasal (onset within 2 minutes)
- Transdermal patches (for chronic pain) 1
Other Fentanyl Analogues
- Some fentanyl analogues can be up to 10,000 times more potent than morphine 3
- These ultra-potent formulations are typically not used in routine clinical practice due to safety concerns
Clinical Comparison with Hydromorphone
Hydromorphone Properties
- Hydromorphone is approximately 7.5 times more potent than oral morphine 1, 4
- When given intravenously, hydromorphone is about 8.5 times more potent than morphine 4
- Recommended in emergency settings at a dose of 0.015 mg/kg IV due to quicker onset and less risk of toxicity in renal failure 1
Fentanyl Advantages
- Faster onset of action compared to hydromorphone
- Lower incidence of side effects in some studies
- Better suited for acute moderate to severe pain due to higher potency and lipid solubility 5
- Safe alternative for patients with morphine allergies 1
- Particularly useful when rapid pain control is needed 1
Clinical Decision Making
When to Choose Fentanyl Over Hydromorphone
- For rapid pain control in emergency settings 5, 1
- In patients with renal impairment (fentanyl has no active metabolites requiring renal clearance) 1
- When transdermal or transmucosal routes are preferred 1, 2
- For procedural pain requiring short duration of action 1
Cautions with Stronger Opioids
- Respiratory depression risk increases with potency
- Close monitoring required, especially with fentanyl due to its high potency 1
- Start with lower doses and titrate carefully
- Have naloxone readily available when administering high-potency opioids 1
Practical Dosing Considerations
- Initial fentanyl dose: 1 mcg/kg IV, followed by ~30 mcg every 5 minutes as needed 1
- For opioid-naïve patients, use extreme caution when initiating fentanyl
- When converting from hydromorphone to fentanyl, use appropriate equianalgesic conversion tables and reduce the calculated dose by 25-50% initially to account for incomplete cross-tolerance
While hydromorphone is a potent opioid analgesic commonly used for moderate to severe pain, fentanyl represents a significantly stronger option when more potent analgesia is required or when hydromorphone is ineffective or contraindicated.