Drug interactions
Carbinoxamine + Diphenhydramine
Severity: Moderate
Carbinoxamine and Diphenhydramine: 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
Both drugs are first-generation sedating antihistamines with anticholinergic properties. Using them together duplicates therapy and increases drowsiness, dry mouth, blurred vision, urinary retention and confusion. Children and older adults are especially vulnerable.
What this interaction means in plain words
Carbinoxamine and Diphenhydramine 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.
Carbinoxamine belongs to Respiratory; Diphenhydramine belongs to Respiratory.
Why it happens
Additive central H1 receptor blockade and additive antimuscarinic effects.
What to do
Avoid using two sedating antihistamines together, and also check for diphenhydramine in over-the-counter cold and sleep products. Keep to one agent.
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 Diphenhydramine
Other interactions of Carbinoxamine
- Alprazolam + Carbinoxamine Moderate
- Amisulpride + Carbinoxamine Moderate
- Amitriptyline + Carbinoxamine Moderate
- Amobarbital + Carbinoxamine Moderate
- Asenapine + Carbinoxamine Moderate
- Azelastine-fluticasone + Carbinoxamine Moderate
Frequently asked questions
Can I take Carbinoxamine with Diphenhydramine?
MediHelp rates the interaction as moderate. Carbinoxamine and Diphenhydramine 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. Both drugs are first-generation sedating antihistamines with anticholinergic properties. Using them together duplicates therapy and increases drowsiness, dry mouth, blurred vision, urinary retention and confusion. Children and older adults are especially vulnerable.
How serious is the interaction between Carbinoxamine and Diphenhydramine?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Avoid using two sedating antihistamines together, and also check for diphenhydramine in over-the-counter cold and sleep products. Keep to one agent.
What other medicines interact with Diphenhydramine?
MediHelp also lists interactions of Diphenhydramine with, for example, Alfentanil, Belladonna and opium, Benzhydrocodone / acetaminophen. The full list is on the Diphenhydramine page.
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