From the Guidelines
Morphine milligram equivalency (MME) is a crucial tool for healthcare providers to compare the potency of different opioid medications and ensure safe prescribing practices, with the most recent and highest quality study providing the conversion factors 1. When converting between opioids, clinicians multiply the dose of the prescribed opioid by a conversion factor to determine the equivalent morphine dose.
- 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 For example, oxycodone is approximately 1.5 times more potent than morphine, so 10mg of oxycodone equals about 15mg MME.
- Higher MME values indicate stronger medications and greater risk for adverse effects.
- Clinicians use MME calculations when rotating opioids, assessing total daily opioid burden, and identifying patients at higher risk for overdose (particularly those exceeding 90 MME daily) 1. These calculations are essential but require clinical judgment, as individual patient factors like tolerance, organ function, and medication interactions can affect how patients respond to opioids. MME conversions should be considered approximate guidelines rather than exact equivalents when making clinical decisions about pain management, and the most recent guidelines should be consulted for the most up-to-date information 1.
From the Research
Morphine Milligram Equivalency
Morphine milligram equivalency (MME) is a measure used to compare the potency of different opioid medications. It is defined as the amount of morphine that would be equivalent in analgesic effect to a given dose of another opioid medication 2.
Importance of MME
The use of MME is important in clinical practice to ensure that patients receive adequate pain relief while minimizing the risk of overdose and addiction. It is also useful for monitoring and surveillance of opioid prescribing patterns, particularly in the context of the opioid crisis 3.
Calculation of MME
The calculation of MME involves converting the dose of a given opioid medication to its equivalent dose in morphine. This can be done using a variety of methods, including the use of conversion tables or algorithms 2, 4.
Factors Affecting MME
Several factors can affect the MME of a given opioid medication, including the patient's individual characteristics, such as weight and renal function, as well as the specific formulation and dosage of the medication 5, 6.
Key Points
- MME is a measure of the potency of opioid medications relative to morphine
- MME is important for ensuring adequate pain relief and minimizing the risk of overdose and addiction
- MME can be calculated using conversion tables or algorithms
- Several factors can affect the MME of a given opioid medication, including patient characteristics and medication formulation
- The use of MME can help to standardize opioid prescribing patterns and facilitate monitoring and surveillance 2, 4, 3
Applications of MME
The use of MME has several applications, including:
- Clinical practice: to ensure that patients receive adequate pain relief while minimizing the risk of overdose and addiction
- Research: to compare the efficacy and safety of different opioid medications
- Public health: to monitor and surveillance of opioid prescribing patterns and to develop strategies to prevent overdose and addiction 2, 4, 3