Drug interactions
Orphenadrine + Oxybutynin
Severity: Moderate
Orphenadrine and Oxybutynin: 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
Orphenadrine has substantial anticholinergic activity, and combining it with oxybutynin can cause additive dry mouth, constipation, urinary retention, tachycardia and confusion. Elderly patients are at particular risk of delirium.
What this interaction means in plain words
Orphenadrine and Oxybutynin 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 antimuscarinic effects.
What to do
Avoid the combination in older adults where possible; otherwise monitor for anticholinergic toxicity and use the lowest doses.
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 Oxybutynin
Frequently asked questions
Can I take Orphenadrine with Oxybutynin?
MediHelp rates the interaction as moderate. Orphenadrine and Oxybutynin 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. Orphenadrine has substantial anticholinergic activity, and combining it with oxybutynin can cause additive dry mouth, constipation, urinary retention, tachycardia and confusion. Elderly patients are at particular risk of delirium.
How serious is the interaction between Orphenadrine and Oxybutynin?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Avoid the combination in older adults where possible; otherwise monitor for anticholinergic toxicity and use the lowest doses.
What other medicines interact with Oxybutynin?
MediHelp also lists interactions of Oxybutynin with, for example, Bethanechol, Clozapine, Potassium chloride. The full list is on the Oxybutynin page.
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