Drug interactions
Chlorpheniramine + Fentanyl transdermal
Severity: Major
Chlorpheniramine 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
Chlorpheniramine adds to the sedative effect of fentanyl, raising the risk of drowsiness and respiratory depression. Patch effects continue for many hours after removal.
What this interaction means in plain words
Chlorpheniramine 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
Additive CNS depression from an opioid and a sedating antihistamine.
What to do
Prefer a non-sedating antihistamine. If combined, use the lowest effective doses and monitor for sedation and 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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Other interactions of Chlorpheniramine
Frequently asked questions
Can I take Chlorpheniramine with Fentanyl transdermal?
MediHelp rates the interaction as major. Chlorpheniramine 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. Chlorpheniramine adds to the sedative effect of fentanyl, raising the risk of drowsiness and respiratory depression. Patch effects continue for many hours after removal.
How serious is the interaction between Chlorpheniramine 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: Prefer a non-sedating antihistamine. If combined, use the lowest effective doses and monitor for sedation and respiratory depression.
What other medicines interact with Chlorpheniramine?
MediHelp also lists interactions of Chlorpheniramine with, for example, Belladonna and opium, Benzhydrocodone / acetaminophen, Brexanolone. The full list is on the Chlorpheniramine page.
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