Drug interactions
Benztropine + Orphenadrine
Severity: Moderate
Benztropine and Orphenadrine: 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
Orphenadrine has substantial anticholinergic activity, so with benztropine the antimuscarinic effects are additive. Confusion, agitation, tachycardia, dry mouth, constipation and urinary retention may occur, particularly in older patients.
What this interaction means in plain words
Benztropine and Orphenadrine 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 muscarinic receptor antagonism.
What to do
Avoid duplicating anticholinergic therapy where possible. If both are needed, monitor for central and peripheral anticholinergic toxicity and use the lowest doses.
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 Orphenadrine, 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 7 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
Frequently asked questions
Can I take Benztropine with Orphenadrine?
MediHelp rates the interaction as moderate. Benztropine and Orphenadrine 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. Orphenadrine has substantial anticholinergic activity, so with benztropine the antimuscarinic effects are additive. Confusion, agitation, tachycardia, dry mouth, constipation and urinary retention may occur, particularly in older patients.
How serious is the interaction between Benztropine and Orphenadrine?
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 duplicating anticholinergic therapy where possible. If both are needed, monitor for central and peripheral anticholinergic toxicity and use the lowest doses.
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.
