Drug interactions
Amoxapine + Fluphenazine
Severity: Major
Amoxapine and Fluphenazine: major interaction.
Last updated Sources: US FDA label
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
Both drugs can prolong the QTc interval and amoxapine also has dopamine-blocking activity. Combined use increases the risk of arrhythmia and extrapyramidal effects, along with additive sedation and anticholinergic effects.
What this interaction means in plain words
Amoxapine and Fluphenazine can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for.
Why it happens
Additive QT prolongation and additive dopamine antagonism; fluphenazine may inhibit CYP2D6 and raise amoxapine levels.
What to do
Avoid if feasible and use an alternative antidepressant. If combined, monitor ECG, electrolytes and extrapyramidal symptoms.
What to ask your pharmacist
- Does the benefit of taking both outweigh the risk in my case?
- Do I need any blood test, ECG or other check while on both?
- What early warning signs should I watch for, and what should I do if they appear?
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References
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 Amoxapine with Fluphenazine?
MediHelp rates the interaction as major. Amoxapine and Fluphenazine can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for. Both drugs can prolong the QTc interval and amoxapine also has dopamine-blocking activity. Combined use increases the risk of arrhythmia and extrapyramidal effects, along with additive sedation and anticholinergic effects.
How serious is the interaction between Amoxapine and Fluphenazine?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Avoid if feasible and use an alternative antidepressant. If combined, monitor ECG, electrolytes and extrapyramidal symptoms.
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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