How many mg of oxycodone equals a 25 mcg/h fentanyl patch?

A 25 mcg/h fentanyl patch corresponds to roughly 60–90 mg oral morphine equivalents per day, which is about 40–60 mg/day of oral oxycodone. Fentanyl conversions use ranges, not a single factor, because absorption varies between patients.

Who should NOT be started on a fentanyl patch?

Opioid-naïve patients. Transdermal fentanyl is only appropriate for patients already tolerant to at least ~60 mg oral morphine equivalents per day for a week or more. Starting a patch in a naïve patient can cause fatal respiratory depression.

When does a new fentanyl patch start working?

Serum levels rise slowly over 12–24 hours after the first patch is applied. Continue short-acting opioid coverage during that window, and do not titrate the patch more often than every 3 days.

Oxycodone to Fentanyl (transdermal patch): how to convert safely

Name: Oxycodone to Fentanyl (transdermal patch) Conversion | scopeMD
Creator: Yasmine Abbey, MD, MSc

Bottom line

Each 25 mcg/h of transdermal fentanyl ≈ 60–90 mg oral morphine equivalents/day. Fentanyl conversions use ranges, not a single factor — and patches are only for opioid-tolerant patients (≥60 OME/day for ≥1 week).

Patch sizes vs. oxycodone equivalents

Patch (mcg/h)	≈ OME (mg/day)	≈ oral oxycodone (mg/day)
12	29–43	19–29
25	60–90	40–60
37	89–133	59–89
50	120–180	80–120
62	149–223	99–149
75	180–270	120–180
100	240–360	160–240

Ranges reflect the commonly used 25 mcg/h ≈ 60–90 OME/day equivalence; verify against your institutional table.

Method: rotating onto the patch

Confirm opioid tolerance (≥60 OME/day for ≥1 week) — patches are never for naïve patients.
Total the 24-hour oxycodone dose and convert to OME (factor 1.5).
Select the patch using the conservative end of the range and round DOWN to an available size.
Continue short-acting coverage for the first 12–24 h while levels rise; do not re-titrate the patch sooner than 3 days.

Cautions

Fentanyl patches are only for opioid-tolerant patients (≥60 OME/day for ≥1 week). Applying a patch to an opioid-naïve patient can be fatal.
Absorption takes 12–24 h to reach steady state and continues 12–24 h after removal — overlap short-acting coverage on the way up, and do not stack doses on the way down.
Fever, external heat sources, and broken skin all increase absorption unpredictably.
Oxycodone is metabolized by CYP3A4 and CYP2D6 — strong CYP3A4 inhibitors (azoles, clarithromycin, some antivirals) can raise levels substantially.
No parenteral form is available in the US; if the patient will lose enteral access, plan the rotation to an IV-capable agent before it happens.

Build the full regimen

The opioid regimen builder handles fentanyl patch selection from a mixed home regimen, including rounding to available patch sizes and frail-patient reductions.

Frequently asked questions

How many mg of oxycodone equals a 25 mcg/h fentanyl patch?: A 25 mcg/h fentanyl patch corresponds to roughly 60–90 mg oral morphine equivalents per day, which is about 40–60 mg/day of oral oxycodone. Fentanyl conversions use ranges, not a single factor, because absorption varies between patients.
Who should NOT be started on a fentanyl patch?: Opioid-naïve patients. Transdermal fentanyl is only appropriate for patients already tolerant to at least ~60 mg oral morphine equivalents per day for a week or more. Starting a patch in a naïve patient can cause fatal respiratory depression.
When does a new fentanyl patch start working?: Serum levels rise slowly over 12–24 hours after the first patch is applied. Continue short-acting opioid coverage during that window, and do not titrate the patch more often than every 3 days.

Créé et maintenu par Yasmine Abbey, MD, MSc · Dernière revue: 2026-08-05

Aide éducative à la décision destinée aux cliniciens. Ne constitue pas un avis médical — vérifiez les résultats au regard de votre jugement clinique, des protocoles de votre établissement et des recommandations en vigueur.