Classification of Opioid Medications and Morphine Equivalent Conversion Factors per Milligram of Opioid*
| Major Group | Type of Opioid | Morphine Equivalent Conversion Factor/Milligram of Opioid |
|---|---|---|
| Short-acting, non-schedule II | Propoxyphene (with or without aspirin/acetaminophen/ibuprofen) | 0.23 |
| Codeine + acetaminophen, ibuprofen, or aspirin | 0.15 | |
| Hydrocodone + acetaminophen, ibuprofen, aspirin, or homatropine | 1.00 | |
| Tramadol with or without aspirin | 0.10 | |
| Butalbital and codeine (with or without aspirin, ibuprofen, acetaminophen) | 0.15 | |
| Dihydrocodeine (with or without aspirin, ibuprofen, acetaminophen) | 0.25 | |
| Pentazocine (with or without aspirin, ibuprofen, acetaminophen) | 0.37 | |
| Short-acting, schedule II | Morphine sulfate | 1.00 |
| Codeine sulfate | 0.15 | |
| Oxycodone (with or without aspirin, ibuprofen, acetaminophen) | 1.50 | |
| Hydromorphone | 4.00 | |
| Meperidine hydrochloride | 0.10 | |
| Fentanyl citrate transmucosal† | 0.125 | |
| Oxymorphone | 3.00 | |
| Long-acting, schedule II | Morphine sulfate sustained release | 1.00 |
| Fentanyl transdermal‡ | 2.40 | |
| Levorphanol tartrate | 11.0 | |
| Oxycodone HCl controlled release | 1.50 | |
| Methadone | 3.00 |
↵* Opioids delivered by pill, capsule, liquid, transdermal patch, and transmucosal administration were included. Opioids formulated for administration by injection or suppository were not included.
↵† Transmucosal fentanyl conversion to morphine equivalents assumes 50% bioavailability of transmucosal fentanyl, and 100-μg transmucosal fentanyl is equivalent to 12.5 to 15 mg of oral morphine.
↵‡ Transdermal fentanyl conversion to morphine equivalent is based on the assumption that one patch delivers the dispensed micrograms/hour over a 24-hour day and remains in place for 3 days.
Adapted from Von Korff M, Saunders K, Ray GT, et al. De facto long-term opioid therapy for noncancer pain. Clin J Pain 2008;24:521–7.19.