From the Guidelines
The most accurate and up-to-date morphine equivalent list is provided in the 2022 CDC clinical practice guideline for prescribing opioids for pain, which includes conversion factors for commonly prescribed opioids such as codeine (0.15), hydrocodone (1.0), oxycodone (1.5), and others 1. When determining morphine milligram equivalents (MMEs), it is essential to consider the conversion factors for each opioid, as outlined in the guideline.
- The conversion factors are as follows:
- 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 These conversion factors can be used to calculate the MME dose for each opioid, which is crucial for preventing overdosing or underdosing when switching medications 1. However, it is critical to note that these conversions should be used with caution, as individual patient responses may vary based on factors such as tolerance, metabolism, and cross-tolerance between different opioids.
- When converting between opioids, it is generally recommended to reduce the calculated equivalent dose by 25-50% initially to account for incomplete cross-tolerance, then titrate as needed based on patient response 1. Additionally, particular caution should be exercised when converting methadone doses due to its long and variable half-life, and when using transdermal fentanyl, as its absorption can be affected by heat and other factors 1.
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 equivalent list is as follows:
- Morphine: 10 mg (IM), 60 mg (PO)
- Hydromorphone: 1.5 mg (IM), 7.5 mg (PO)
- Methadone: 10 mg (IM), 20 mg (PO)
- Oxycodone: 15 mg (IM), 30 mg (PO)
- Levorphanol: 2 mg (IM), 4 mg (PO)
- Oxymorphone: 1 mg (IM), 10 mg (PO)
- Meperidine: 75 mg (IM)
- Codeine: 130 mg (IM), 200 mg (PO) 2
From the Research
Opioid Equivalents
The following opioids are commonly used for pain management:
- Morphine
- Codeine
- Fentanyl
- Hydrocodone
- Hydromorphone
- Methadone
- Oxycodone
- Tramadol
- Tapentadol 3
Morphine Equivalent List
While there is no direct list of morphine equivalents provided in the studies, the following information can be used to compare the potency of different opioids:
- Fentanyl is a potent opioid, often used for breakthrough pain episodes 4
- Hydromorphone, fentanyl, and oxycodone can be considered as alternatives to morphine for first-line therapy 4
- Methadone has complex pharmacology and should be restricted to patients with difficult pain syndromes 4
- Oxycodone and naloxone combination is available for reduction of opioid-induced constipation 4
- Tramadol and codeine have unique pharmacodynamic properties leading to acute toxicity and dependence development 5
Opioid Potency and Conversion
The potency of opioids can vary greatly, and conversion between different opioids should be done with caution:
- No consistent placebo or active control was found in the studies, making comparative analyses impossible 3
- The amount and quality of evidence around the use of opioids for treating cancer pain is disappointingly low 3
- Pharmacogenomics may play a role in opioid dosing and treatment outcomes, but more research is needed 6
- Drug interactions should be considered when using opioids, especially with other central nervous system depressants 7