Drug interactions
Carbamazepine + Fentanyl transmucosal
Severity: Major
Carbamazepine and Fentanyl transmucosal: major interaction.
Last updated Sources: US FDA label
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
Carbamazepine reduces fentanyl exposure, which may cause inadequate breakthrough pain relief or withdrawal. Discontinuing carbamazepine can raise fentanyl levels and prolong opioid effects.
What this interaction means in plain words
Carbamazepine and Fentanyl transmucosal 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
Carbamazepine induces CYP3A4, increasing fentanyl clearance.
What to do
Monitor analgesic effect and titrate fentanyl. When carbamazepine is stopped, lower the fentanyl dose and watch for respiratory depression.
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?
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References
Other interactions of Carbamazepine
- Artemether / lumefantrine + Carbamazepine Contraindicated
- Cabotegravir + Carbamazepine Contraindicated
- Carbamazepine + Delamanid Contraindicated
- Carbamazepine + Dienogest / estradiol valerate Contraindicated
- Carbamazepine + Doravirine Contraindicated
- Carbamazepine + Elbasvir / grazoprevir Contraindicated
Frequently asked questions
Can I take Carbamazepine with Fentanyl transmucosal?
MediHelp rates the interaction as major. Carbamazepine and Fentanyl transmucosal 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. Carbamazepine reduces fentanyl exposure, which may cause inadequate breakthrough pain relief or withdrawal. Discontinuing carbamazepine can raise fentanyl levels and prolong opioid effects.
How serious is the interaction between Carbamazepine and Fentanyl transmucosal?
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 analgesic effect and titrate fentanyl. When carbamazepine is stopped, lower the fentanyl dose and watch for respiratory depression.
What other medicines interact with Carbamazepine?
MediHelp also lists interactions of Carbamazepine with, for example, Artemether / lumefantrine, Cabotegravir, Delamanid. The full list is on the Carbamazepine page.
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