Drug interactions
Chlorpheniramine + Fentanyl
Severity: Moderate
Chlorpheniramine and Fentanyl: moderate 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 is a sedating first-generation antihistamine that can add to the drowsiness and respiratory depression caused by fentanyl. Anticholinergic effects may also worsen confusion in older adults.
What this interaction means in plain words
Chlorpheniramine and Fentanyl can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken.
Chlorpheniramine belongs to Respiratory; Fentanyl belongs to Musculoskeletal.
Why it happens
Additive CNS depression from sedating antihistamine and opioid effects.
What to do
Prefer a non-sedating antihistamine where an antihistamine is needed. Otherwise monitor for sedation and advise against driving.
What to ask your pharmacist
- Should I take them at different times of day?
- Does the dose of either medicine need to change?
- Is there anything I should avoid, such as alcohol or certain foods, while on both?
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Other interactions of Fentanyl
- Alvimopan + Fentanyl Contraindicated
- Fentanyl + Isocarboxazid Contraindicated
- Fentanyl + Olanzapine / samidorphan Contraindicated
- Fentanyl + Phenelzine Contraindicated
- Fentanyl + Tranylcypromine Contraindicated
- Alfentanil + Fentanyl Major
Other interactions of Chlorpheniramine
Frequently asked questions
Can I take Chlorpheniramine with Fentanyl?
MediHelp rates the interaction as moderate. Chlorpheniramine and Fentanyl can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken. Chlorpheniramine is a sedating first-generation antihistamine that can add to the drowsiness and respiratory depression caused by fentanyl. Anticholinergic effects may also worsen confusion in older adults.
How serious is the interaction between Chlorpheniramine and Fentanyl?
MediHelp rates it moderate, 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 where an antihistamine is needed. Otherwise monitor for sedation and advise against driving.
What other medicines interact with Fentanyl?
MediHelp also lists interactions of Fentanyl with, for example, Alvimopan, Isocarboxazid, Olanzapine / samidorphan. The full list is on the Fentanyl page.
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