Drug interactions
Fluphenazine + Oxybutynin
Severity: Moderate
Fluphenazine and Oxybutynin: 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
Fluphenazine has anticholinergic activity, though lower than some other phenothiazines, so combined use with oxybutynin can add to constipation, dry mouth, urinary retention and confusion. Elderly patients are at higher risk.
What this interaction means in plain words
Fluphenazine and Oxybutynin 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.
Fluphenazine belongs to Central Nervous System; Oxybutynin belongs to Genitourinary.
Why it happens
Additive antimuscarinic effects.
What to do
Monitor for anticholinergic effects and bowel function. Use the lowest effective doses.
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 Oxybutynin
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 Oxybutynin?
MediHelp rates the interaction as moderate. Fluphenazine and Oxybutynin 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. Fluphenazine has anticholinergic activity, though lower than some other phenothiazines, so combined use with oxybutynin can add to constipation, dry mouth, urinary retention and confusion. Elderly patients are at higher risk.
How serious is the interaction between Fluphenazine and Oxybutynin?
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 effects and bowel function. Use the lowest effective doses.
What other medicines interact with Oxybutynin?
MediHelp also lists interactions of Oxybutynin with, for example, Bethanechol, Clozapine, Potassium chloride. The full list is on the Oxybutynin page.
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