Drug interactions
Primaquine + Saquinavir
Severity: Major
Primaquine and Saquinavir: 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 QT interval, so giving them together may increase the risk of torsades de pointes and other serious ventricular arrhythmias. The risk is greater with electrolyte disturbances, heart disease or other QT-prolonging drugs.
What this interaction means in plain words
Primaquine 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 pharmacodynamic QT prolongation through effects on cardiac repolarization.
What to do
Avoid the combination where possible and consider an alternative antimalarial or antiretroviral. If unavoidable, obtain a baseline ECG, correct potassium and magnesium, and monitor the QTc during therapy.
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 Primaquine
- Pimozide + Primaquine Contraindicated
- Amiodarone + Primaquine Major
- Amisulpride + Primaquine Major
- Anagrelide + Primaquine Major
- Arsenic trioxide + Primaquine Major
- Asenapine + Primaquine Major
Frequently asked questions
Can I take Primaquine with Saquinavir?
MediHelp rates the interaction as major. Primaquine 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. Both drugs can prolong the QT interval, so giving them together may increase the risk of torsades de pointes and other serious ventricular arrhythmias. The risk is greater with electrolyte disturbances, heart disease or other QT-prolonging drugs.
How serious is the interaction between Primaquine 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 the combination where possible and consider an alternative antimalarial or antiretroviral. If unavoidable, obtain a baseline ECG, correct potassium and magnesium, and monitor the QTc during therapy.
What other medicines interact with Primaquine?
MediHelp also lists interactions of Primaquine with, for example, Pimozide, Amiodarone, Amisulpride. The full list is on the Primaquine page.
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