Drug interactions
Clonazepam + Fentanyl iontophoretic transdermal system
Severity: Major
Clonazepam and Fentanyl iontophoretic transdermal system: 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
Using a benzodiazepine with fentanyl increases the risk of profound sedation and respiratory depression. The combination has been associated with deaths.
What this interaction means in plain words
Clonazepam and Fentanyl iontophoretic transdermal system 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
Additive CNS and respiratory depression from opioid receptor agonism and GABA-A potentiation.
What to do
Use only when alternatives are inadequate, at the lowest effective doses. Monitor for sedation and respiratory depression, especially in opioid-naive patients.
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 Clonazepam
- Calcium / magnesium / potassium / sodium oxybates + Clonazepam Contraindicated
- Clonazepam + Sodium oxybate Contraindicated
- Alfentanil + Clonazepam Major
- Alprazolam + Clonazepam Major
- Amobarbital + Clonazepam Major
- Belladonna and opium + Clonazepam Major
Frequently asked questions
Can I take Clonazepam with Fentanyl iontophoretic transdermal system?
MediHelp rates the interaction as major. Clonazepam and Fentanyl iontophoretic transdermal system 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. Using a benzodiazepine with fentanyl increases the risk of profound sedation and respiratory depression. The combination has been associated with deaths.
How serious is the interaction between Clonazepam and Fentanyl iontophoretic transdermal system?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Use only when alternatives are inadequate, at the lowest effective doses. Monitor for sedation and respiratory depression, especially in opioid-naive patients.
What other medicines interact with Clonazepam?
MediHelp also lists interactions of Clonazepam with, for example, Calcium / magnesium / potassium / sodium oxybates, Sodium oxybate, Alfentanil. The full list is on the Clonazepam page.
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