Drug interactions
Hyoscyamine + Tolterodine
Severity: Moderate
Hyoscyamine and Tolterodine: 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 agents are antimuscarinics, so combining them produces additive anticholinergic effects including dry mouth, constipation, urinary retention, blurred vision and confusion.
What this interaction means in plain words
Hyoscyamine and Tolterodine 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.
Hyoscyamine belongs to Genitourinary; Tolterodine belongs to Genitourinary.
Why it happens
Additive antimuscarinic pharmacodynamic effects.
What to do
Avoid duplicate antimuscarinic therapy; if combined, monitor for anticholinergic toxicity and reduce doses as needed.
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 Tolterodine
Other interactions of Hyoscyamine
- Amantadine + Hyoscyamine Moderate
- Amitriptyline + Hyoscyamine Moderate
- Aripiprazole + Hyoscyamine Moderate
- Atropine + Hyoscyamine Moderate
- Benztropine + Hyoscyamine Moderate
- Bethanechol + Hyoscyamine Moderate
Frequently asked questions
Can I take Hyoscyamine with Tolterodine?
MediHelp rates the interaction as moderate. Hyoscyamine and Tolterodine 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 agents are antimuscarinics, so combining them produces additive anticholinergic effects including dry mouth, constipation, urinary retention, blurred vision and confusion.
How serious is the interaction between Hyoscyamine and Tolterodine?
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 duplicate antimuscarinic therapy; if combined, monitor for anticholinergic toxicity and reduce doses as needed.
What other medicines interact with Tolterodine?
MediHelp also lists interactions of Tolterodine with, for example, Clarithromycin, Clozapine, Cobicistat. The full list is on the Tolterodine page.
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