Drug interactions
Belladonna alkaloids + Perphenazine
Severity: Moderate
Belladonna alkaloids and Perphenazine: 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
Belladonna alkaloids are antimuscarinic and perphenazine has anticholinergic properties, so additive effects such as dry mouth, constipation, urinary retention, blurred vision, tachycardia and confusion can occur. Reduced gut motility may also lower oral perphenazine absorption.
What this interaction means in plain words
Belladonna alkaloids and Perphenazine 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, with anticholinergic delay of GI transit potentially reducing perphenazine absorption.
What to do
Monitor for anticholinergic toxicity and for loss of antipsychotic control. Use the lowest effective doses and take particular care in elderly patients or those 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 Perphenazine
- Ibutilide + Perphenazine Contraindicated
- Perphenazine + Pimozide Contraindicated
- Perphenazine + Thioridazine Contraindicated
- Adagrasib + Perphenazine Major
- Alfentanil + Perphenazine Major
- Amiodarone + Perphenazine Major
Frequently asked questions
Can I take Belladonna alkaloids with Perphenazine?
MediHelp rates the interaction as moderate. Belladonna alkaloids and Perphenazine 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. Belladonna alkaloids are antimuscarinic and perphenazine has anticholinergic properties, so additive effects such as dry mouth, constipation, urinary retention, blurred vision, tachycardia and confusion can occur. Reduced gut motility may also lower oral perphenazine absorption.
How serious is the interaction between Belladonna alkaloids and Perphenazine?
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 and for loss of antipsychotic control. Use the lowest effective doses and take particular care in elderly patients or those with glaucoma or urinary obstruction.
What other medicines interact with Perphenazine?
MediHelp also lists interactions of Perphenazine with, for example, Ibutilide, Pimozide, Thioridazine. The full list is on the Perphenazine page.
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