Drug interactions
Chlorpheniramine + Diazepam
Severity: Moderate
Chlorpheniramine and Diazepam: 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 antihistamine that can add to the drowsiness and psychomotor impairment of diazepam. Older adults may also experience confusion and anticholinergic effects.
What this interaction means in plain words
Chlorpheniramine and Diazepam 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; Diazepam belongs to Musculoskeletal.
Why it happens
Additive CNS depression from central H1 antagonism and GABA-A potentiation.
What to do
Advise avoiding driving and alcohol, and prefer a non-sedating antihistamine when possible. Monitor older patients for confusion and falls.
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 Diazepam
Other interactions of Chlorpheniramine
Frequently asked questions
Can I take Chlorpheniramine with Diazepam?
MediHelp rates the interaction as moderate. Chlorpheniramine and Diazepam 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 antihistamine that can add to the drowsiness and psychomotor impairment of diazepam. Older adults may also experience confusion and anticholinergic effects.
How serious is the interaction between Chlorpheniramine and Diazepam?
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 avoiding driving and alcohol, and prefer a non-sedating antihistamine when possible. Monitor older patients for confusion and falls.
What other medicines interact with Diazepam?
MediHelp also lists interactions of Diazepam with, for example, Calcium / magnesium / potassium / sodium oxybates, Alfentanil, Alprazolam. The full list is on the Diazepam page.
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