Drug interactions
Cyclizine + Trihexyphenidyl
Severity: Moderate
Cyclizine 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
Cyclizine is an antihistamine with antimuscarinic properties and adds to the anticholinergic burden of trihexyphenidyl. This can cause confusion, sedation, dry mouth, tachycardia and urinary retention.
What this interaction means in plain words
Cyclizine 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.
Cyclizine belongs to Respiratory; Trihexyphenidyl belongs to Central Nervous System.
Why it happens
Additive antimuscarinic effects.
What to do
Monitor for anticholinergic toxicity, especially in older adults, and consider a non-anticholinergic antiemetic such as ondansetron if appropriate.
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
Other interactions of Cyclizine
- Calcium / magnesium / potassium / sodium oxybates + Cyclizine Major
- Cyclizine + Henbane Major
- Cyclizine + Sodium oxybate Major
- Abobotulinumtoxina + Cyclizine Moderate
- Alfentanil + Cyclizine Moderate
- Alprazolam + Cyclizine Moderate
Frequently asked questions
Can I take Cyclizine with Trihexyphenidyl?
MediHelp rates the interaction as moderate. Cyclizine 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. Cyclizine is an antihistamine with antimuscarinic properties and adds to the anticholinergic burden of trihexyphenidyl. This can cause confusion, sedation, dry mouth, tachycardia and urinary retention.
How serious is the interaction between Cyclizine 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 toxicity, especially in older adults, and consider a non-anticholinergic antiemetic such as ondansetron if appropriate.
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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