Drug interactions
Benztropine + Hyoscyamine
Severity: Moderate
Benztropine and Hyoscyamine: 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 block muscarinic receptors, so taking them together adds to anticholinergic effects such as dry mouth, blurred vision, constipation, urinary retention, tachycardia and confusion. Older adults and patients with glaucoma, prostatic enlargement or reduced gut motility are at greatest risk.
What this interaction means in plain words
Benztropine and Hyoscyamine 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; Hyoscyamine belongs to Genitourinary.
Why it happens
Additive antagonism at muscarinic acetylcholine receptors (pharmacodynamic synergism).
What to do
Monitor for urinary retention, constipation, hyperthermia and cognitive changes, and use the lowest effective doses. Consider stopping one agent if peripheral or central anticholinergic toxicity appears.
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 Benztropine
- Benztropine + Memantine-donepezil Major
- Abobotulinumtoxina + Benztropine Moderate
- Amantadine + Benztropine Moderate
- Amitriptyline + Benztropine Moderate
- Amoxapine + Benztropine Moderate
- Atropine iv / + Benztropine Moderate
Other interactions of Hyoscyamine
- Amantadine + Hyoscyamine Moderate
- Amitriptyline + Hyoscyamine Moderate
- Aripiprazole + Hyoscyamine Moderate
- Atropine + Hyoscyamine Moderate
- Bethanechol + Hyoscyamine Moderate
- Carbidopa-entacapone-levodopa + Hyoscyamine Moderate
Frequently asked questions
Can I take Benztropine with Hyoscyamine?
MediHelp rates the interaction as moderate. Benztropine and Hyoscyamine 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 block muscarinic receptors, so taking them together adds to anticholinergic effects such as dry mouth, blurred vision, constipation, urinary retention, tachycardia and confusion. Older adults and patients with glaucoma, prostatic enlargement or reduced gut motility are at greatest risk.
How serious is the interaction between Benztropine and Hyoscyamine?
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 urinary retention, constipation, hyperthermia and cognitive changes, and use the lowest effective doses. Consider stopping one agent if peripheral or central anticholinergic toxicity appears.
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.
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