Drug interactions
Chlorpheniramine + Lenacapavir
Severity: Minor
Chlorpheniramine and Lenacapavir: minor 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
Lenacapavir is a moderate CYP3A inhibitor and may increase chlorpheniramine concentrations. This may enhance sedation and anticholinergic effects, and the inhibition can persist for months after subcutaneous dosing.
What this interaction means in plain words
Chlorpheniramine and Lenacapavir have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised.
Chlorpheniramine belongs to Respiratory; Lenacapavir belongs to Anti Virals.
Why it happens
Inhibition of CYP3A4 by lenacapavir reduces chlorpheniramine clearance.
What to do
Monitor for drowsiness and anticholinergic symptoms and reduce the antihistamine dose if needed. A non-sedating antihistamine is an option for prolonged use.
What to ask your pharmacist
- Is there anything I should notice while taking both?
- Do I need to tell my doctor at the next visit?
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Other interactions of Chlorpheniramine
Other interactions of Lenacapavir
- Apalutamide + Lenacapavir Contraindicated
- Carbamazepine + Lenacapavir Contraindicated
- Enzalutamide + Lenacapavir Contraindicated
- Flibanserin + Lenacapavir Contraindicated
- Lenacapavir + Phenytoin Contraindicated
- Lenacapavir + Rifampicin Contraindicated
Frequently asked questions
Can I take Chlorpheniramine with Lenacapavir?
MediHelp rates the interaction as minor. Chlorpheniramine and Lenacapavir have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised. Lenacapavir is a moderate CYP3A inhibitor and may increase chlorpheniramine concentrations. This may enhance sedation and anticholinergic effects, and the inhibition can persist for months after subcutaneous dosing.
How serious is the interaction between Chlorpheniramine and Lenacapavir?
MediHelp rates it minor, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Monitor for drowsiness and anticholinergic symptoms and reduce the antihistamine dose if needed. A non-sedating antihistamine is an option for prolonged use.
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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