Drug interactions
Chlorpheniramine + Elvitegravir / cobicistat / emtricitabine / tenofovir df
Severity: Minor
Chlorpheniramine and Elvitegravir / cobicistat / emtricitabine / tenofovir df: 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
Cobicistat is a strong CYP3A inhibitor and may raise chlorpheniramine concentrations, increasing sedation and anticholinergic effects. The effect is generally manageable.
What this interaction means in plain words
Chlorpheniramine and Elvitegravir / cobicistat / emtricitabine / tenofovir df have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised.
Why it happens
Cobicistat inhibition of CYP3A4 (and CYP2D6) reduces chlorpheniramine metabolism.
What to do
Monitor for excess drowsiness and anticholinergic effects and reduce the chlorpheniramine dose or choose a non-sedating antihistamine if they occur.
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
Frequently asked questions
Can I take Chlorpheniramine with Elvitegravir / cobicistat / emtricitabine / tenofovir df?
MediHelp rates the interaction as minor. Chlorpheniramine and Elvitegravir / cobicistat / emtricitabine / tenofovir df have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised. Cobicistat is a strong CYP3A inhibitor and may raise chlorpheniramine concentrations, increasing sedation and anticholinergic effects. The effect is generally manageable.
How serious is the interaction between Chlorpheniramine and Elvitegravir / cobicistat / emtricitabine / tenofovir df?
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 excess drowsiness and anticholinergic effects and reduce the chlorpheniramine dose or choose a non-sedating antihistamine if they occur.
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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