Drug interactions
Henbane + Perphenazine
Severity: Moderate
Henbane 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
Henbane contains the antimuscarinic alkaloids hyoscyamine and scopolamine, which add to the anticholinergic burden of perphenazine. This may cause dry mouth, constipation, urinary retention, confusion and tachycardia, and may increase the risk of delirium in older patients.
What this interaction means in plain words
Henbane 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; reduced gastric motility may also modestly alter oral absorption of perphenazine.
What to do
Avoid the combination where possible, especially in older patients. If used, monitor for anticholinergic toxicity and for loss of antipsychotic control.
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 Henbane with Perphenazine?
MediHelp rates the interaction as moderate. Henbane 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. Henbane contains the antimuscarinic alkaloids hyoscyamine and scopolamine, which add to the anticholinergic burden of perphenazine. This may cause dry mouth, constipation, urinary retention, confusion and tachycardia, and may increase the risk of delirium in older patients.
How serious is the interaction between Henbane 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: Avoid the combination where possible, especially in older patients. If used, monitor for anticholinergic toxicity and for loss of antipsychotic control.
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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