Drug interactions
Primaquine + Quinacrine
Severity: Major
Primaquine and Quinacrine: 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
Quinacrine has been reported to raise primaquine plasma concentrations and increase its toxicity, including gastrointestinal effects and possibly haemolysis. The mechanism is not well characterised.
What this interaction means in plain words
Primaquine and Quinacrine 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
Mechanism not firmly established; reduced primaquine clearance is suspected.
What to do
Avoid the combination. If it cannot be avoided, monitor the blood count and for methaemoglobinaemia and gastrointestinal 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 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 Quinacrine?
MediHelp rates the interaction as major. Primaquine and Quinacrine 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. Quinacrine has been reported to raise primaquine plasma concentrations and increase its toxicity, including gastrointestinal effects and possibly haemolysis. The mechanism is not well characterised.
How serious is the interaction between Primaquine and Quinacrine?
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. If it cannot be avoided, monitor the blood count and for methaemoglobinaemia and gastrointestinal toxicity.
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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