Drug interactions
Fluphenazine + Protriptyline
Severity: Major
Fluphenazine and Protriptyline: 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
Fluphenazine and the tricyclic antidepressant protriptyline both can prolong the QT interval and cause arrhythmias. Phenothiazines may also raise tricyclic concentrations via CYP2D6 inhibition, and anticholinergic effects add up.
What this interaction means in plain words
Fluphenazine and Protriptyline 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, plus possible CYP2D6 inhibition by fluphenazine raising protriptyline exposure.
What to do
Avoid the combination when possible. If both are required, check ECG at baseline and after dose changes, correct electrolytes, and monitor for anticholinergic and cardiac toxicity.
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 Fluphenazine with Protriptyline?
MediHelp rates the interaction as major. Fluphenazine and Protriptyline 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. Fluphenazine and the tricyclic antidepressant protriptyline both can prolong the QT interval and cause arrhythmias. Phenothiazines may also raise tricyclic concentrations via CYP2D6 inhibition, and anticholinergic effects add up.
How serious is the interaction between Fluphenazine and Protriptyline?
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 the combination when possible. If both are required, check ECG at baseline and after dose changes, correct electrolytes, and monitor for anticholinergic and cardiac toxicity.
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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