Drug interactions
Carbachol + Tolterodine
Severity: Moderate
Carbachol 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
Carbachol is a cholinergic agonist and tolterodine is a muscarinic antagonist, so they have opposing pharmacologic effects. Tolterodine may reduce the effect of carbachol and the combination may lessen the therapeutic effect of either drug.
What this interaction means in plain words
Carbachol 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.
Carbachol belongs to Miscellaneous; Tolterodine belongs to Genitourinary.
Why it happens
Pharmacodynamic antagonism at muscarinic receptors.
What to do
Monitor for reduced effect of carbachol, such as reduced pupil constriction or bladder stimulation. Avoid concurrent use when possible or adjust therapy based on response.
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 Carbachol
- Atropine + Carbachol Moderate
- Bethanechol + Carbachol Moderate
- Carbachol + Darifenacin Moderate
- Carbachol + Dicyclomine Moderate
- Carbachol + Donepezil Moderate
- Carbachol + Flavoxate Moderate
Frequently asked questions
Can I take Carbachol with Tolterodine?
MediHelp rates the interaction as moderate. Carbachol 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. Carbachol is a cholinergic agonist and tolterodine is a muscarinic antagonist, so they have opposing pharmacologic effects. Tolterodine may reduce the effect of carbachol and the combination may lessen the therapeutic effect of either drug.
How serious is the interaction between Carbachol 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: Monitor for reduced effect of carbachol, such as reduced pupil constriction or bladder stimulation. Avoid concurrent use when possible or adjust therapy based on response.
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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