Drug interactions
Fluphenazine + Phendimetrazine
Severity: Moderate
Fluphenazine and Phendimetrazine: 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
Phendimetrazine is a sympathomimetic anorectic, and antipsychotics can blunt stimulant effects while stimulants may worsen psychosis. Both agents can also affect heart rate and rhythm, so cardiovascular effects could be additive in predisposed patients. The interaction is poorly characterized.
What this interaction means in plain words
Fluphenazine and Phendimetrazine 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
Opposing dopaminergic and adrenergic pharmacology with possible additive cardiac effects; the exact mechanism is not firmly established.
What to do
Monitor heart rate, blood pressure and mental status, and avoid the combination in patients with arrhythmia or psychosis that is not stable. Consider a non-stimulant weight-loss approach if possible.
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 Phendimetrazine?
MediHelp rates the interaction as moderate. Fluphenazine and Phendimetrazine 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. Phendimetrazine is a sympathomimetic anorectic, and antipsychotics can blunt stimulant effects while stimulants may worsen psychosis. Both agents can also affect heart rate and rhythm, so cardiovascular effects could be additive in predisposed patients. The interaction is poorly characterized.
How serious is the interaction between Fluphenazine and Phendimetrazine?
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 heart rate, blood pressure and mental status, and avoid the combination in patients with arrhythmia or psychosis that is not stable. Consider a non-stimulant weight-loss approach if possible.
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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