Drug interactions
Clozapine + Oxybutynin
Severity: Major
Clozapine and Oxybutynin: major 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
Clozapine is highly anticholinergic, and combining it with oxybutynin raises the risk of constipation, which can progress to serious bowel hypomotility or ileus, as well as urinary retention, tachycardia and delirium. Clozapine-related gastrointestinal complications can be severe.
What this interaction means in plain words
Clozapine and Oxybutynin can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for.
Clozapine belongs to Central Nervous System; Oxybutynin belongs to Genitourinary.
Why it happens
Additive antimuscarinic effects on gut, bladder and central nervous system.
What to do
Avoid the combination where possible; if used, monitor bowel function closely and give laxatives proactively. Reassess the need for oxybutynin and consider non-anticholinergic options for urinary symptoms.
What to ask your pharmacist
- Does the benefit of taking both outweigh the risk in my case?
- Do I need any blood test, ECG or other check while on both?
- What early warning signs should I watch for, and what should I do if they appear?
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Other interactions of Oxybutynin
- Bethanechol + Oxybutynin Major
- Oxybutynin + Potassium chloride Major
- Oxybutynin + Rivastigmine Major
- Oxybutynin + Trihexyphenidyl Major
- Abobotulinumtoxina + Oxybutynin Moderate
- Aclidinium + Oxybutynin Moderate
Other interactions of Clozapine
- Clozapine + Deferiprone Contraindicated
- Clozapine + Irinotecan Contraindicated
- Clozapine + Pimozide Contraindicated
- Clozapine + Thioridazine Contraindicated
- Acalabrutinib + Clozapine Major
- Adagrasib + Clozapine Major
Frequently asked questions
Can I take Clozapine with Oxybutynin?
MediHelp rates the interaction as major. Clozapine and Oxybutynin can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for. Clozapine is highly anticholinergic, and combining it with oxybutynin raises the risk of constipation, which can progress to serious bowel hypomotility or ileus, as well as urinary retention, tachycardia and delirium. Clozapine-related gastrointestinal complications can be severe.
How serious is the interaction between Clozapine and Oxybutynin?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Avoid the combination where possible; if used, monitor bowel function closely and give laxatives proactively. Reassess the need for oxybutynin and consider non-anticholinergic options for urinary symptoms.
What other medicines interact with Oxybutynin?
MediHelp also lists interactions of Oxybutynin with, for example, Bethanechol, Potassium chloride, Rivastigmine. The full list is on the Oxybutynin page.
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