Drug interactions
Diltiazem + Fentanyl transdermal
Severity: Major
Diltiazem and Fentanyl transdermal: 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
Diltiazem can raise fentanyl concentrations, and with a transdermal patch the effect is prolonged and may lead to serious respiratory depression.
What this interaction means in plain words
Diltiazem 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
Diltiazem inhibits CYP3A4-mediated fentanyl metabolism.
What to do
Monitor for respiratory depression and sedation, and reduce the fentanyl dose if needed. Remember effects persist after patch removal.
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 Diltiazem
- Diltiazem + Flibanserin Contraindicated
- Diltiazem + Ivabradine Contraindicated
- Diltiazem + Lomitapide Contraindicated
- Diltiazem + Lonafarnib Contraindicated
- Acebutolol + Diltiazem Major
- Alfentanil + Diltiazem Major
Frequently asked questions
Can I take Diltiazem with Fentanyl transdermal?
MediHelp rates the interaction as major. Diltiazem 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. Diltiazem can raise fentanyl concentrations, and with a transdermal patch the effect is prolonged and may lead to serious respiratory depression.
How serious is the interaction between Diltiazem 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 for respiratory depression and sedation, and reduce the fentanyl dose if needed. Remember effects persist after patch removal.
What other medicines interact with Diltiazem?
MediHelp also lists interactions of Diltiazem with, for example, Flibanserin, Ivabradine, Lomitapide. The full list is on the Diltiazem page.
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