Drug interactions
Benztropine + Homatropine
Severity: Moderate
Benztropine 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, often combined with hydrocodone in cough preparations, that adds to benztropine's anticholinergic effects. This may cause dry mouth, constipation, urinary retention, tachycardia and confusion.
What this interaction means in plain words
Benztropine 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.
Benztropine belongs to Central Nervous System; Homatropine belongs to Genitourinary.
Why it happens
Additive antimuscarinic effects.
What to do
Monitor for anticholinergic toxicity, particularly in older patients, and limit the duration of homatropine-containing products.
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?
Pro+ members
Unlock the full page
Create an account and start a Pro+ trial to unlock the full management advice for Benztropine and Homatropine, the additional notes, the evidence detail and the whole-prescription interaction checker.
- Full clinical management advice
- Additional notes
- Evidence detail
- Interaction checker for a whole prescription
Try Pro+ free for 14 days on the web. No card needed.
Other interactions of Benztropine
- Benztropine + Memantine-donepezil Major
- Abobotulinumtoxina + Benztropine Moderate
- Amantadine + Benztropine Moderate
- Amitriptyline + Benztropine Moderate
- Amoxapine + Benztropine Moderate
- Atropine iv / + Benztropine Moderate
Other interactions of Homatropine
- Amantadine + Homatropine Moderate
- Amitriptyline + Homatropine Moderate
- Atropine + Homatropine Moderate
- Bethanechol + Homatropine Moderate
- Chlorpromazine + Homatropine Moderate
- Clomipramine + Homatropine Moderate
Frequently asked questions
Can I take Benztropine with Homatropine?
MediHelp rates the interaction as moderate. Benztropine 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, often combined with hydrocodone in cough preparations, that adds to benztropine's anticholinergic effects. This may cause dry mouth, constipation, urinary retention, tachycardia and confusion.
How serious is the interaction between Benztropine 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 anticholinergic toxicity, particularly in older patients, and limit the duration of homatropine-containing products.
What other medicines interact with Benztropine?
MediHelp also lists interactions of Benztropine with, for example, Memantine-donepezil, Abobotulinumtoxina, Amantadine. The full list is on the Benztropine page.
Full monographs, dosing and an interaction checker in the MediHelp app
Open the complete reference, check multi-drug interactions and use dosing tools in the MediHelp app.
