Drug interactions
Chloramphenicol + Fentanyl transdermal
Severity: Major
Chloramphenicol and Fentanyl transdermal: major interaction.
Last updated
For healthcare professionals — reference only. This page is a brief summary, not medical advice and not a substitute for official labeling or clinical judgement. Always verify before prescribing or dispensing.
Summary
Chloramphenicol inhibits CYP3A4 and can reduce fentanyl clearance, so serum fentanyl rises, and the patch depot prolongs the exposure. This can cause profound sedation and respiratory depression that may persist after the antibiotic is stopped.
What this interaction means in plain words
Chloramphenicol and Fentanyl transdermal can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for.
Why it happens
Inhibition of CYP3A4-mediated fentanyl metabolism.
What to do
Monitor closely for respiratory depression and sedation during and after chloramphenicol, and reduce the patch dose or switch to a less CYP3A4-dependent opioid if needed.
What to ask your pharmacist
- Does the benefit of taking both outweigh the risk in my case?
- Do I need any blood test, ECG or other check while on both?
- What early warning signs should I watch for, and what should I do if they appear?
Pro+ members
Unlock the full page
Create an account and start a Pro+ trial to unlock the full management advice for Chloramphenicol and Fentanyl transdermal, the additional notes, the evidence detail and the whole-prescription interaction checker.
- Full clinical management advice
- Additional notes
- Evidence detail
- Interaction checker for a whole prescription
Try Pro+ free for 7 days on the web. No card needed.
Other interactions of Chloramphenicol
Frequently asked questions
Can I take Chloramphenicol with Fentanyl transdermal?
MediHelp rates the interaction as major. Chloramphenicol and Fentanyl transdermal can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for. Chloramphenicol inhibits CYP3A4 and can reduce fentanyl clearance, so serum fentanyl rises, and the patch depot prolongs the exposure. This can cause profound sedation and respiratory depression that may persist after the antibiotic is stopped.
How serious is the interaction between Chloramphenicol and Fentanyl transdermal?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Monitor closely for respiratory depression and sedation during and after chloramphenicol, and reduce the patch dose or switch to a less CYP3A4-dependent opioid if needed.
What other medicines interact with Chloramphenicol?
MediHelp also lists interactions of Chloramphenicol with, for example, Adagrasib, Avapritinib, Bcg vaccine live. The full list is on the Chloramphenicol page.
Full monographs, dosing and an interaction checker in the MediHelp app
Open the complete reference, check multi-drug interactions and use dosing tools in the MediHelp app.
