Drug interactions
Fluphenazine + Saquinavir
Severity: Major
Fluphenazine and Saquinavir: major 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
Saquinavir prolongs the QT and PR intervals, and fluphenazine is also associated with QT prolongation. Saquinavir is a strong CYP3A4 inhibitor and may also raise fluphenazine levels, increasing the risk of arrhythmia and extrapyramidal effects.
What this interaction means in plain words
Fluphenazine and Saquinavir 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, with possible pharmacokinetic increase in fluphenazine exposure from saquinavir enzyme inhibition.
What to do
Avoid if possible and choose an alternative antipsychotic or antiretroviral. If coadministered, obtain a baseline ECG, monitor QTc and electrolytes, and watch for fluphenazine 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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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 Saquinavir?
MediHelp rates the interaction as major. Fluphenazine and Saquinavir 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. Saquinavir prolongs the QT and PR intervals, and fluphenazine is also associated with QT prolongation. Saquinavir is a strong CYP3A4 inhibitor and may also raise fluphenazine levels, increasing the risk of arrhythmia and extrapyramidal effects.
How serious is the interaction between Fluphenazine and Saquinavir?
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 possible and choose an alternative antipsychotic or antiretroviral. If coadministered, obtain a baseline ECG, monitor QTc and electrolytes, and watch for fluphenazine 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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