Drug interactions
Quinine + Saquinavir
Severity: Major
Quinine 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
Ritonavir-boosted saquinavir strongly inhibits CYP3A4 and can raise quinine concentrations, while both drugs prolong the QT interval. This increases the risk of torsades de pointes and cinchonism.
What this interaction means in plain words
Quinine 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
CYP3A4 inhibition raising quinine exposure plus additive QT prolongation.
What to do
Avoid if possible; if unavoidable, monitor ECG and electrolytes and consider reducing the quinine dose.
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 Quinine
- Arsenic trioxide + Quinine Contraindicated
- Dofetilide + Quinine Contraindicated
- Dronedarone + Quinine Contraindicated
- Ibutilide + Quinine Contraindicated
- Mefloquine + Quinine Contraindicated
- Nilotinib + Quinine Contraindicated
Frequently asked questions
Can I take Quinine with Saquinavir?
MediHelp rates the interaction as major. Quinine 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. Ritonavir-boosted saquinavir strongly inhibits CYP3A4 and can raise quinine concentrations, while both drugs prolong the QT interval. This increases the risk of torsades de pointes and cinchonism.
How serious is the interaction between Quinine 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; if unavoidable, monitor ECG and electrolytes and consider reducing the quinine dose.
What other medicines interact with Quinine?
MediHelp also lists interactions of Quinine with, for example, Arsenic trioxide, Dofetilide, Dronedarone. The full list is on the Quinine page.
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