Drug interactions
Glycopyrrolate + Trihexyphenidyl
Severity: Moderate
Glycopyrrolate 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 agents are antimuscarinic, so combined use can intensify dry mouth, constipation, urinary retention, tachycardia and blurred vision. Glycopyrrolate acts mainly peripherally, while trihexyphenidyl adds central effects such as confusion.
What this interaction means in plain words
Glycopyrrolate 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.
Glycopyrrolate belongs to Respiratory; Trihexyphenidyl belongs to Central Nervous System.
Why it happens
Additive muscarinic receptor antagonism.
What to do
Monitor for peripheral anticholinergic effects and heat intolerance, and reduce the dose of one drug if adverse effects develop.
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 Glycopyrrolate and Trihexyphenidyl, 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 Trihexyphenidyl
Other interactions of Glycopyrrolate
- Glycopyrrolate + Potassium chloride Major
- Amitriptyline + Glycopyrrolate Moderate
- Atropine + Glycopyrrolate Moderate
- Bethanechol + Glycopyrrolate Moderate
- Chlorpromazine + Glycopyrrolate Moderate
- Clomipramine + Glycopyrrolate Moderate
Frequently asked questions
Can I take Glycopyrrolate with Trihexyphenidyl?
MediHelp rates the interaction as moderate. Glycopyrrolate 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 agents are antimuscarinic, so combined use can intensify dry mouth, constipation, urinary retention, tachycardia and blurred vision. Glycopyrrolate acts mainly peripherally, while trihexyphenidyl adds central effects such as confusion.
How serious is the interaction between Glycopyrrolate 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 anticholinergic effects and heat intolerance, and reduce the dose of one drug if adverse effects develop.
What other medicines interact with Trihexyphenidyl?
MediHelp also lists interactions of Trihexyphenidyl with, for example, Orphenadrin, Oxybutynin, Scopolamine. The full list is on the Trihexyphenidyl 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.
