Drug interactions
Fluphenazine + Orphenadrine
Severity: Moderate
Fluphenazine 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
Orphenadrine has anticholinergic and sedative properties, and fluphenazine is a sedating antipsychotic with its own anticholinergic activity. Together they can increase drowsiness, confusion, dry mouth, constipation and urinary retention. Orphenadrine is often used deliberately to treat antipsychotic-induced parkinsonism, but the additive burden is greater in older adults.
What this interaction means in plain words
Fluphenazine 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 central nervous system depression and anticholinergic effects through muscarinic and histaminergic blockade.
What to do
Monitor for oversedation, cognitive impairment and anticholinergic effects, and use the lowest effective orphenadrine dose. Reassess the need for orphenadrine regularly, especially in elderly patients.
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 Fluphenazine
- Arsenic trioxide + Fluphenazine Contraindicated
- Dofetilide + Fluphenazine Contraindicated
- Fluphenazine + Ibutilide Contraindicated
- Fluphenazine + Pimozide Contraindicated
- Adagrasib + Fluphenazine Major
- Alfentanil + Fluphenazine Major
Frequently asked questions
Can I take Fluphenazine with Orphenadrine?
MediHelp rates the interaction as moderate. Fluphenazine 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. Orphenadrine has anticholinergic and sedative properties, and fluphenazine is a sedating antipsychotic with its own anticholinergic activity. Together they can increase drowsiness, confusion, dry mouth, constipation and urinary retention. Orphenadrine is often used deliberately to treat antipsychotic-induced parkinsonism, but the additive burden is greater in older adults.
How serious is the interaction between Fluphenazine 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 oversedation, cognitive impairment and anticholinergic effects, and use the lowest effective orphenadrine dose. Reassess the need for orphenadrine regularly, especially in elderly patients.
What other medicines interact with Fluphenazine?
MediHelp also lists interactions of Fluphenazine with, for example, Arsenic trioxide, Dofetilide, Ibutilide. The full list is on the Fluphenazine page.
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