Levorphanol and Fentanyl Transdermal Patch: Interaction Details
AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Levorphanol
Fentanyl Transdermal Patch
How we grade severity & evidence
Severity levels
- Contraindicated: These should generally not be used together.
- Major: Potentially serious — often needs a change or close monitoring.
- Moderate: Can be significant — usually manageable with monitoring.
- Minor: Usually limited clinical impact.
Evidence grades
- Established: Well documented — supported by controlled studies or strong clinical data.
- Probable: Good supporting evidence, though not definitively proven.
- Suspected: Some evidence suggests this interaction, but it is not well established.
- Possible: Limited or conflicting evidence; the interaction may occur.
- Theoretical: Predicted from the drugs' pharmacology; not yet confirmed in people.
Ratings come from the documented interaction literature and are reviewed by a pharmacist. They describe the documented risk of the combination, not what will necessarily happen to you — your dose, timing, and health picture all matter.
What happens
Increased risk of respiratory and CNS depression and an increased risk of serotonin syndrome
Interaction Deep Dive
Concomitant use of fentaNYL and a serotonergic CNS depressant may result in an increased risk of serotonin syndrome, profound sedation, respiratory depression, hypotension, coma and death3. Reserve concomitant use of fentaNYL and CNS depressants for whom alternatives are inadequate. If concomitant use is necessary, prescribe the lowest effective dosages and minimum durations of concomitant use and titrate the dosages based on clinical response. Monitor the patients for sedation, respiratory depression, and signs and symptoms of serotonin syndrome. Discontinue fentaNYL if serotonin syndrome is suspected. If concomitant use is warranted, consider prescribing naloxone for the emergency treatment of opioid overdose 415. As postoperative analgesia, start with a lower dose of fentaNYL injection and monitor patients for signs of respiratory depression, sedation, and hypotension. Keep fluids and other measures readily available to treat potential hypotension 3.
Why it happens (mechanism)
Additive CNS depression; additive serotonergic effects
Literature reports
1 report — tap to read
a) Observational studies have demonstrated that concomitant use of opioid analgesics and benzodiazepines increases the risk of drug-related mortality compared to use of opioid analgesics alone. Because of similar pharmacological properties, it is reasonable to expect similar risk with the concomitant use of other CNS depressant drugs with opioid analgesics 523.
Common questions
Can I take Levorphanol and Fentanyl Transdermal Patch together?
Increased risk of respiratory and CNS depression and an increased risk of serotonin syndrome Always confirm with your pharmacist or prescriber before making any change.
How serious is the Levorphanol and Fentanyl Transdermal Patch interaction?
It is rated major. Potentially serious — often needs a change or close monitoring.
How quickly could this interaction happen?
The documented onset is "unspecified". The timing of this interaction is not well characterized.
How strong is the evidence for this interaction?
The evidence is graded "theoretical". Predicted from the drugs' pharmacology; not yet confirmed in people.
Questions for your pharmacist
- Does my dose of Levorphanol or Fentanyl Transdermal Patch need adjusting while I take them together?
- What symptoms should prompt me to call you or my prescriber right away?
- Does the timing of my doses matter for this combination?
- Is there a safer alternative to one of these medications for me?
References (5)
- Product Information: ABSTRAL(R) oral sublingual tablets, fentanyl oral sublingual tablets. Sentynl Therapeutics, Inc. (per FDA), Solana Beach, CA, 2016. DailyMed
- Product Information: ACTIQ(R) oral transmucosal lozenge, fentanyl citrate oral transmucosal lozenge. Teva Pharmaceuticals USA, Inc. (per FDA), Parsippany, NJ, 2023. DailyMed
- Product Information: Fentanyl citrate intravenous, intramuscular injection, fentanyl citrate intravenous, intramuscular injection. Hospira Inc (per FDA), Lake Forest, IL, 2023. DailyMed
- Product Information: LAZANDA(R) nasal spray, fentanyl citrate nasal spray. Depomed Inc (per FDA), Newark, CA, 2016. DailyMed
- Product Information: FENTORA(R) buccal tablets, fentanyl citrate buccal tablets. Teva Pharmaceuticals USA Inc (per FDA), Parsippany, NJ, 2023.
Keep reading about Levorphanol
Keep reading about Fentanyl Transdermal Patch
These medications also interact with supplements
Prescription drugs aren't the whole picture — herbal and dietary supplements can interact with them too. From the evidence-graded Natural Medicines database:
major · moderate · minor — check everything you take with our drug–supplement interaction checker.
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