Drug interactions
Clozapine + Orphenadrine
Severity: Moderate
Clozapine and Orphenadrine: 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 have anticholinergic and sedating properties, so combined use can increase drowsiness and anticholinergic toxicity such as constipation, urinary retention, confusion and tachycardia. Clozapine-related severe constipation and ileus can be worsened.
What this interaction means in plain words
Clozapine and Orphenadrine 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 and CNS depressant effects.
What to do
Monitor for sedation, bowel function, urinary retention and cognitive changes, and consider an alternative muscle relaxant with less anticholinergic activity. Reduce the dose if symptoms appear.
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 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 Orphenadrine?
MediHelp rates the interaction as moderate. Clozapine and Orphenadrine 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 have anticholinergic and sedating properties, so combined use can increase drowsiness and anticholinergic toxicity such as constipation, urinary retention, confusion and tachycardia. Clozapine-related severe constipation and ileus can be worsened.
How serious is the interaction between Clozapine and Orphenadrine?
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 sedation, bowel function, urinary retention and cognitive changes, and consider an alternative muscle relaxant with less anticholinergic activity. Reduce the dose if symptoms appear.
What other medicines interact with Clozapine?
MediHelp also lists interactions of Clozapine with, for example, Deferiprone, Irinotecan, Pimozide. The full list is on the Clozapine page.
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