Drug interactions
Primaquine + Tucatinib
Severity: Moderate
Primaquine and Tucatinib: 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
Tucatinib is a strong CYP3A inhibitor and may raise primaquine concentrations, although primaquine is only partly metabolized by CYP3A4 and its main pathway is via MAO-A. Higher exposure could increase dose-related adverse effects such as gastrointestinal upset, methemoglobinemia and hemolysis in susceptible patients.
What this interaction means in plain words
Primaquine and Tucatinib 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.
Primaquine belongs to Anti Parasitic; Tucatinib belongs to Oncology.
Why it happens
Inhibition of CYP3A4-mediated metabolism of primaquine by tucatinib.
What to do
Check for G6PD deficiency before primaquine and monitor hemoglobin and for methemoglobinemia signs during co-use. Consider an alternative if toxicity appears.
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?
Pro+ members
Unlock the full page
Create an account and start a Pro+ trial to unlock the full management advice for Primaquine and Tucatinib, the additional notes, the evidence detail and the whole-prescription interaction checker.
- Full clinical management advice
- Additional notes
- Evidence detail
- Interaction checker for a whole prescription
Try Pro+ free for 7 days on the web. No card needed.
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 Tucatinib
- Cisapride + Tucatinib Contraindicated
- Eletriptan + Tucatinib Contraindicated
- Ergotamine + Tucatinib Contraindicated
- Flibanserin + Tucatinib Contraindicated
- Ranolazine + Tucatinib Contraindicated
- Amobarbital + Tucatinib Major
Frequently asked questions
Can I take Primaquine with Tucatinib?
MediHelp rates the interaction as moderate. Primaquine and Tucatinib 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. Tucatinib is a strong CYP3A inhibitor and may raise primaquine concentrations, although primaquine is only partly metabolized by CYP3A4 and its main pathway is via MAO-A. Higher exposure could increase dose-related adverse effects such as gastrointestinal upset, methemoglobinemia and hemolysis in susceptible patients.
How serious is the interaction between Primaquine and Tucatinib?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Check for G6PD deficiency before primaquine and monitor hemoglobin and for methemoglobinemia signs during co-use. Consider an alternative if toxicity appears.
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.
Full monographs, dosing and an interaction checker in the MediHelp app
Open the complete reference, check multi-drug interactions and use dosing tools in the MediHelp app.
