Opioid Equivalencies and Conversions

Opioid Equivalencies and Conversions

OPIOID EQUIVALENCIES AND CONVERSIONS

All opioid equivalencies should be considered approximations only and can be affected by interpatient variability, type of pain (eg, acute vs. chronic), chronic administration, tolerance, etc. Patients should be monitored for efficacy and adverse reactions and the dose adjusted accordingly

 

Morphine Milligram Equivalent (MME) represents the potency of an opioid dose relative to morphine. MME/day determines cumulative intake of opioids, and helps identify patients who may benefit from closer monitoring, reduction of opioid dose, tapering of opioids, or other measures to reduce risk of overdose. The Centers for Disease Control and Prevention cautions when considering increasing dosage to ≥50 MME/day, and should avoid increasing dosage to ≥90 MME/day unless justified.

Generic1 Equianalgesic Dose Opioid Oral MME Conversion Factor3
Oral Injection (IM/IV/SC)2
Natural Opiates
morphine4 30mg (60mg) 10mg 1
codeine 200mg 100mg 0.15
Semisynthetic Opioids
hydrocodone5 30mg 1
hydromorphone 7.5mg 1.5mg 5
oxycodone5 20mg 1.5
oxymorphone 10mg 1mg 3
Synthetic Opioids
fentanyl injection 0.1mg (100mcg)
fentanyl transdermal (mcg/hr) 12mcg/hr patch 2.46
levorphanol 2mg 11
meperidine 300mg 100mg 0.1
methadone 10-20mg7 5-10mg 4-128
tapentadol 75mg 0.4
tramadol 300mg 0.2
NOTES

Key: CR = controlled-release; IR = immediate-release

1 Doses are in mg/day unless otherwise specified.

2 Although controlled studies are not available, in clinical practice it is customary to consider the doses of opioids given IM, IV, or SC to be equivalent. There may be some differences in pharmacokinetic parameters such as Cmax and Tmax.

3 Not to be used to determine dosage for converting one opioid to another or for converting between fentanyl products.

4 The conversion ratio of 10mg parenteral morphine = 30mg oral morphine is based on clinical experience in patients with chronic pain. The conversion ratio of 10mg parenteral morphine = 60mg oral morphine is based on a potency study in acute pain.

5 Available as a single-entity product and combination products.

6 The conversion factors for other fentanyl formulations are as follows: buccal or SL tab/lozenge/troche (mcg) = 0.13; film or oral spray (mcg) = 0.18; nasal spray (mcg) = 0.16. For transdermal patches, the conversion factor needs to be multiplied by 3 since the patch remains in place for 3 days.

7 There is limited evidence and no consensus on the conversion of methadone. A 3:1 equianalgesic dose ratio (morphine:methadone) at lower doses, but higher conversion ratios that increase at higher doses (eg, 5:1, 8:1, 10:1, 12:1, 15:1) have been used. Caution should be used with methadone dose conversions as methadone has a long and variable half-life and peak respiratory effect occurs later and lasts longer than peak analgesic effect.

8 The conversion factor for methadone increases at higher doses: 1–20mg/day = 4; 21–40mg/day = 8; 41–60mg/day = 10; ≥61–80mg/day = 12

REFERENCES

Dowell D, Ragan KR, Jones CM, et al. CDC Clinical Practice Guideline for Prescribing Opioids for Pain — United States, 2022. MMWR Recomm Rep 2022;71(No. RR-3):1–95. DOI: http://dx.doi.org/10.15585/mmwr.rr7103a1. Accessed October 21, 2023.
Feldman MD, Christensen JF, Satterfield JM. Behavioral Medicine: A Guide For Clinical Practice, Fourth Edition. New York, NY: McGraw-Hill Education; 2014.

(Rev.11/2023)