Drug interactions
Methscopolamine + Trihexyphenidyl
Severity: Moderate
Methscopolamine 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 are antimuscarinics, so co-administration increases the likelihood of dry mouth, constipation, urinary retention, tachycardia and blurred vision. Trihexyphenidyl can also add central effects such as confusion.
What this interaction means in plain words
Methscopolamine 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.
Why it happens
Additive muscarinic receptor blockade.
What to do
Monitor for anticholinergic adverse effects and reduce the dose of one drug if they develop; avoid in patients with glaucoma or urinary obstruction.
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 Trihexyphenidyl
Frequently asked questions
Can I take Methscopolamine with Trihexyphenidyl?
MediHelp rates the interaction as moderate. Methscopolamine 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 are antimuscarinics, so co-administration increases the likelihood of dry mouth, constipation, urinary retention, tachycardia and blurred vision. Trihexyphenidyl can also add central effects such as confusion.
How serious is the interaction between Methscopolamine 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 anticholinergic adverse effects and reduce the dose of one drug if they develop; avoid in patients with glaucoma or urinary obstruction.
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.
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