What are the morphine equivalents for different opioids (narcotics)?

From the Guidelines

Morphine equivalents for different narcotics are calculated by multiplying the dose of each opioid by its conversion factor, with morphine being the reference standard at 1.0, as outlined in the 2022 CDC clinical practice guideline for prescribing opioids for pain 1. To determine the morphine milligram equivalent (MME) dose for a specific opioid, the following conversion factors can be used:

• Codeine: 0.15
• Fentanyl transdermal (in mcg/hr): 2.4
• Hydrocodone: 1.0
• Hydromorphone: 5.0
• Methadone: 4.7
• Morphine: 1.0
• Oxycodone: 1.5
• Oxymorphone: 3.0
• Tapentadol: 0.4
• Tramadol: 0.2 For example, a dose of 10mg hydrocodone would be equivalent to 10mg morphine, while a dose of 10mg oxycodone would be equivalent to 15mg morphine. When converting between opioids, it is essential to consider individual patient factors, such as tolerance, kidney function, and concurrent medications, to prevent under-treatment of pain and potential overdose, as noted in the guideline 1. Key considerations when using these conversion factors include:
• Equianalgesic dose conversions are estimates and may not account for individual variability in genetics and pharmacokinetics
• The calculated dose in MMEs should not be used to determine the doses to use when converting one opioid to another
• Particular caution should be used when converting methadone doses due to its long and variable half-life
• Transdermal fentanyl requires special consideration due to its dosing in mcg/hr and potential for variable absorption.

From the FDA Drug Label

TABLE D*,† EQUIANALGESIC POTENCY CONVERSION Name Equianalgesic Dose (mg) IM‡,§ PO Morphine 10 60 (30)¶ Hydromorphone (Dilaudid®) 1.5 7.5 Methadone (Dolophine®) 10 20 Oxycodone 15 30 Levorphanol (Levo-Dromoran®) 2 4 Oxymorphone (Numorphan®) 1 10 (PR) Meperidine (Demerol®) 75 — Codeine 130 200

The morphine equivalents for different narcotics are as follows:

• Hydromorphone (Dilaudid): 1.5 mg IM or 7.5 mg PO is equivalent to 10 mg of morphine
• Methadone (Dolophine): 10 mg IM or 20 mg PO is equivalent to 10 mg of morphine
• Oxycodone: 15 mg IM or 30 mg PO is equivalent to 10 mg of morphine
• Levorphanol (Levo-Dromoran): 2 mg IM or 4 mg PO is equivalent to 10 mg of morphine
• Oxymorphone (Numorphan): 1 mg IM or 10 mg PR is equivalent to 10 mg of morphine
• Meperidine (Demerol): 75 mg IM is equivalent to 10 mg of morphine
• Codeine: 130 mg IM or 200 mg PO is equivalent to 10 mg of morphine 2

From the Research

Morphine Equivalents for Different Narcotics

The following are some morphine equivalents for different narcotics, as reported in various studies:

• Fentanyl:
  • 1,800 mcg (as 75 mcg/hour) transdermal patch is equivalent to approximately 176 mg of morphine 3
  • Mean morphine equivalent doses for fentanyl were 180 mg, 178 mg, and 157 mg for physicians, pharmacists, and nurse practitioners/physician assistants, respectively 3
• Hydrocodone:
  • 80 mg is equivalent to approximately 88 mg of morphine 3
• Hydromorphone:
  • 48 mg is equivalent to approximately 192 mg of morphine 3
• Methadone:
  • 40 mg is equivalent to approximately 193 mg of morphine, with a large standard deviation of 201 mg 3
  • Mean morphine equivalent doses for methadone were 214 mg, 171 mg, and 185 mg for physicians, pharmacists, and nurse practitioners/physician assistants, respectively 3
• Oxycodone:
  • 120 mg is equivalent to approximately 173 mg of morphine 3
  • 5/325 mg or 10/650 mg oral oxycodone/acetaminophen was compared to oral morphine (15 or 30 mg) for pain relief in the emergency department, with no significant difference in satisfaction or pain scores 4

Variability in Opioid Conversions

There is significant variability in opioid conversions to morphine equivalent doses, both within and between different professions, including physicians, pharmacists, and nurse practitioners/physician assistants 3. This variability highlights the need for a standardized method of converting between different opioids to ensure accurate and consistent dosing.

Standardization of Opioid Conversions

Several studies have emphasized the importance of standardizing opioid conversions to morphine equivalent doses, including the use of conversion tables and educational lectures 5, 6. These tools can help improve knowledge and retention of opioid conversions among healthcare professionals, ultimately leading to better pain management and reduced risk of adverse events.

Global Measure of Opioid Availability

A global measure of opioid availability, known as Distributed Opioids in Morphine Equivalents (DOME), has been proposed as a simple indicator to quantify unmet pain relief and palliative care need 7. This measure can be used to evaluate the capacity of health systems to meet the need for palliative care, particularly in low- and middle-income countries.