To determine dose in MMEs, multiply the dose for each opioid by the conversion factor. For example, tablets containing hydrocodone 5 mg and acetaminophen 300 mg taken four times a day would contain a total of 20 mg of hydrocodone daily, equivalent to 20 MME daily; extended-release tablets containing oxycodone 10mg and taken twice a day would contain a total of 20mg of oxycodone daily, equivalent to 30 MME daily.
- All doses should be in mg/day, except for fentanyl which should be in mcg/hr, before multiplying by the conversion factor.
- Equianalgesic dose conversions are only estimates and cannot account for individual variability in genetics and pharmacokinetics.
- Do not use the calculated dose in MMEs to determine the doses to use when converting opioid to another; when converting opioids the new opioid is typically dosed at substantially lower than the calculated MME dose to avoid accidental overdose due to incomplete cross-tolerance and individual variability in opioid pharmacokinetics.
- Use particular caution with methadone dose conversions because the conversion factor increases at higher doses.
- Use particular caution with fentanyl since it is dosed in mcg/hr instead of mg/day, and its absorption is affected by heat and other factors.
SOURCE: Adapted from Von Korff M, Saunders K, Thomas Ray G, et al. De facto long-term opioid therapy for noncancer pain. Clin J Pain. 2008 Jul–Aug; 24(6):521–527 and Washington State interagency guideline on prescribing opioids for pain; 2015.