Drug interactions
Fostemsavir + Primaquine
Severity: Moderate
Fostemsavir and Primaquine: moderate 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
Fostemsavir has been linked to QT prolongation at supratherapeutic doses, and primaquine can also prolong the QT interval. At recommended doses the additive risk is likely low, but caution applies in high-risk patients.
What this interaction means in plain words
Fostemsavir and Primaquine can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken.
Fostemsavir belongs to Anti Virals; Primaquine belongs to Anti Parasitic.
Why it happens
Additive prolongation of cardiac repolarization.
What to do
Use an ECG for patients with congenital long QT, heart disease, or other QT-prolonging drugs, and correct electrolytes. Keep fostemsavir at the recommended dose.
What to ask your pharmacist
- Should I take them at different times of day?
- Does the dose of either medicine need to change?
- Is there anything I should avoid, such as alcohol or certain foods, while on both?
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Other interactions of Primaquine
- Pimozide + Primaquine Contraindicated
- Amiodarone + Primaquine Major
- Amisulpride + Primaquine Major
- Anagrelide + Primaquine Major
- Arsenic trioxide + Primaquine Major
- Asenapine + Primaquine Major
Other interactions of Fostemsavir
- Apalutamide + Fostemsavir Contraindicated
- Carbamazepine + Fostemsavir Contraindicated
- Enzalutamide + Fostemsavir Contraindicated
- Fostemsavir + Mitotane Contraindicated
- Fostemsavir + Phenytoin Contraindicated
- Fostemsavir + Rifampicin Contraindicated
Frequently asked questions
Can I take Fostemsavir with Primaquine?
MediHelp rates the interaction as moderate. Fostemsavir and Primaquine can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken. Fostemsavir has been linked to QT prolongation at supratherapeutic doses, and primaquine can also prolong the QT interval. At recommended doses the additive risk is likely low, but caution applies in high-risk patients.
How serious is the interaction between Fostemsavir and Primaquine?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Use an ECG for patients with congenital long QT, heart disease, or other QT-prolonging drugs, and correct electrolytes. Keep fostemsavir at the recommended dose.
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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