What is the dose comparison for intravenous (IV) fentanyl, intravenous (IV) morphine, and intravenous (IV) hydromorphone?

From the Guidelines

The dose comparison for IV fentanyl, IV morphine, and IV hydromorphone is approximately 100 mcg of fentanyl = 10 mg of morphine = 1.5 mg of hydromorphone, as indicated by the most recent and highest quality study 1. These opioids differ significantly in potency, with hydromorphone being about 7 times more potent than morphine, and fentanyl being roughly 100 times more potent than morphine. For acute pain management in adults, typical starting doses are:

• 25-50 mcg for fentanyl
• 2-4 mg for morphine
• 0.2-0.6 mg for hydromorphone These medications also have different durations of action:
• Fentanyl has a short duration (30-60 minutes)
• Morphine has an intermediate duration (3-4 hours)
• Hydromorphone has a slightly shorter duration than morphine (2-3 hours) When administering these medications, it's essential to titrate to effect while monitoring for respiratory depression, hypotension, and other opioid-related side effects, as recommended by 2 and 3. The onset of action also varies, with fentanyl acting within 1-2 minutes, while morphine and hydromorphone typically take 5-10 minutes to reach peak effect. These differences in pharmacokinetics make each medication suitable for different clinical scenarios, with fentanyl often preferred for brief procedures and morphine or hydromorphone for longer-lasting pain control. Key considerations for conversion between these opioids include:
• Using equianalgesic dose tables to guide conversions, as shown in 1 and 3
• Reducing the dose of the new opioid by 25%-50% to account for individual variability in response, as recommended by 3
• Monitoring closely for signs of overdose or underdose and adjusting the dose accordingly, as emphasized by 2 and 1.

From the Research

Dose Comparison for Intravenous Fentanyl, Morphine, and Hydromorphone

• The dose comparison for intravenous (IV) fentanyl, IV morphine, and IV hydromorphone can be analyzed based on available studies 4, 5, 6, 7, 8.
• A study comparing the effectiveness and safety of fentanyl with morphine for out-of-hospital analgesia found that fentanyl patients received a higher equivalent dose of opioid (9.2 mg morphine equivalents for fentanyl, 7.7 mg for morphine) 4.
• However, there is limited information available on the dose comparison between IV fentanyl, IV morphine, and IV hydromorphone in the provided studies.
• One study found that the mean morphine dose for pain relief was similar in both the acetaminophen and placebo groups (0.15 mg/kg and 0.16 mg/kg, respectively) 5.
• Another study compared patient-controlled analgesia (PCA) morphine with IV morphine and found that PCA morphine reduced the pain compared to IV morphine in low and high dosages, but only two studies were involved 6.
• A guideline for prehospital pain management recommended the use of either IV fentanyl or IV morphine, but did not provide specific dose comparisons 7.
• A study comparing two doses of morphine (0.10 mg/kg and 0.15 mg/kg) found that the higher dose resulted in significant reduction in final pain after 1 hour 8.

Key Findings

• Fentanyl patients received a higher equivalent dose of opioid compared to morphine patients 4.
• The mean morphine dose for pain relief was similar in both the acetaminophen and placebo groups 5.
• PCA morphine reduced the pain compared to IV morphine in low and high dosages, but only two studies were involved 6.
• The guideline for prehospital pain management recommended the use of either IV fentanyl or IV morphine, but did not provide specific dose comparisons 7.
• The higher dose of morphine (0.15 mg/kg) resulted in significant reduction in final pain after 1 hour 8.