Drug interactions
Imipramine + Trihexyphenidyl
Severity: Moderate
Imipramine and Trihexyphenidyl: 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 have strong antimuscarinic activity, so combining them adds to the anticholinergic burden. This can cause dry mouth, constipation, urinary retention, blurred vision, tachycardia, confusion and delirium, especially in older patients.
What this interaction means in plain words
Imipramine and Trihexyphenidyl 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.
Imipramine belongs to Central Nervous System; Trihexyphenidyl belongs to Central Nervous System.
Why it happens
Additive blockade of muscarinic cholinergic receptors.
What to do
Monitor for peripheral and central anticholinergic effects and use the lowest effective doses. Reduce the trihexyphenidyl dose or choose an alternative antidepressant in elderly patients or those with glaucoma, urinary retention or cognitive impairment.
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 Imipramine
- Dronedarone + Imipramine Contraindicated
- Imipramine + Isocarboxazid Contraindicated
- Imipramine + Phenelzine Contraindicated
- Imipramine + Pimozide Contraindicated
- Imipramine + Rasagiline Contraindicated
- Imipramine + Safinamide Contraindicated
Other interactions of Trihexyphenidyl
Frequently asked questions
Can I take Imipramine with Trihexyphenidyl?
MediHelp rates the interaction as moderate. Imipramine and Trihexyphenidyl 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 have strong antimuscarinic activity, so combining them adds to the anticholinergic burden. This can cause dry mouth, constipation, urinary retention, blurred vision, tachycardia, confusion and delirium, especially in older patients.
How serious is the interaction between Imipramine and Trihexyphenidyl?
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 peripheral and central anticholinergic effects and use the lowest effective doses. Reduce the trihexyphenidyl dose or choose an alternative antidepressant in elderly patients or those with glaucoma, urinary retention or cognitive impairment.
What other medicines interact with Imipramine?
MediHelp also lists interactions of Imipramine with, for example, Dronedarone, Isocarboxazid, Phenelzine. The full list is on the Imipramine page.
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