Drug interactions
Primaquine + Tetracaine
Severity: Moderate
Primaquine and Tetracaine: 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
Primaquine can cause methemoglobinemia, particularly in G6PD-deficient patients, and local anesthetics such as tetracaine can also induce it. Combined exposure may increase the risk of clinically significant methemoglobinemia with hypoxia and cyanosis.
What this interaction means in plain words
Primaquine and Tetracaine 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; Tetracaine belongs to Central Nervous System.
Why it happens
Additive oxidative stress on hemoglobin, producing methemoglobin.
What to do
Check G6PD status before primaquine and use the lowest effective tetracaine dose. Monitor for cyanosis and falling oxygen saturation, and give methylene blue if significant methemoglobinemia occurs, except in G6PD deficiency.
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 Tetracaine
- Chloroquine + Tetracaine Moderate
- Dapsone + Tetracaine Moderate
- Isosorbide dinitrate + Tetracaine Moderate
- Isosorbide mononitrate + Tetracaine Moderate
- Nitrofurantoin + Tetracaine Moderate
- Nitroglycerin + Tetracaine Moderate
Frequently asked questions
Can I take Primaquine with Tetracaine?
MediHelp rates the interaction as moderate. Primaquine and Tetracaine 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 can cause methemoglobinemia, particularly in G6PD-deficient patients, and local anesthetics such as tetracaine can also induce it. Combined exposure may increase the risk of clinically significant methemoglobinemia with hypoxia and cyanosis.
How serious is the interaction between Primaquine and Tetracaine?
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 G6PD status before primaquine and use the lowest effective tetracaine dose. Monitor for cyanosis and falling oxygen saturation, and give methylene blue if significant methemoglobinemia occurs, except in G6PD deficiency.
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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