Drug interactions
Chlorpheniramine + Marijuana
Severity: Moderate
Chlorpheniramine and Marijuana: 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, and cannabis also causes drowsiness and psychomotor impairment. Together they may produce additive sedation, dizziness and reduced alertness, impairing driving and other safety-sensitive tasks.
What this interaction means in plain words
Chlorpheniramine and Marijuana 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.
Why it happens
Additive central nervous system depression from H1 antagonism and cannabinoid receptor activity.
What to do
Advise patients to avoid driving or operating machinery until their response is known. Counsel against using cannabis with sedating antihistamines, or use a non-sedating antihistamine.
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 Chlorpheniramine
Frequently asked questions
Can I take Chlorpheniramine with Marijuana?
MediHelp rates the interaction as moderate. Chlorpheniramine and Marijuana 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, and cannabis also causes drowsiness and psychomotor impairment. Together they may produce additive sedation, dizziness and reduced alertness, impairing driving and other safety-sensitive tasks.
How serious is the interaction between Chlorpheniramine and Marijuana?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Advise patients to avoid driving or operating machinery until their response is known. Counsel against using cannabis with sedating antihistamines, or use a non-sedating antihistamine.
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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