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Drug interactions

Amantadine + Homatropine

Severity: Moderate

Amantadine and Homatropine: 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

Homatropine is an antimuscarinic, and when given systemically (for example in combination cough products) it can add to amantadine's anticholinergic and CNS effects. This may cause confusion, dry mouth, urinary retention and tachycardia.

What this interaction means in plain words

Amantadine and Homatropine 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.

Amantadine belongs to Anti Virals; Homatropine belongs to Genitourinary.

Evidence level: Low

Why it happens

Additive anticholinergic pharmacodynamic effects.

What to do

Monitor for confusion and urinary retention, and consider alternatives in older patients.

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?

Bring a full list of your medicines, including over-the-counter products, supplements and herbal remedies, to every pharmacy visit.

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Frequently asked questions

Can I take Amantadine with Homatropine?

MediHelp rates the interaction as moderate. Amantadine and Homatropine 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. Homatropine is an antimuscarinic, and when given systemically (for example in combination cough products) it can add to amantadine's anticholinergic and CNS effects. This may cause confusion, dry mouth, urinary retention and tachycardia.

How serious is the interaction between Amantadine and Homatropine?

MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Monitor for confusion and urinary retention, and consider alternatives in older patients.

What other medicines interact with Amantadine?

MediHelp also lists interactions of Amantadine with, for example, Ethanol, Memantine-donepezil, Metoclopramide. The full list is on the Amantadine page.

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