Drug interactions
Erythromycin + Primaquine
Severity: Moderate
Erythromycin 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
Both drugs have been associated with QT prolongation, so combined use may increase the risk of ventricular arrhythmias including torsades de pointes. Risk is higher with electrolyte abnormalities or underlying heart disease.
What this interaction means in plain words
Erythromycin 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.
Erythromycin belongs to Anti Bacterial; Primaquine belongs to Anti Parasitic.
Why it happens
Additive effects on cardiac repolarization leading to QT prolongation.
What to do
Obtain a baseline ECG and correct hypokalemia and hypomagnesemia before starting. Consider a non-macrolide antibiotic in patients with other QT risk factors.
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 Erythromycin
- Conivaptan + Erythromycin Contraindicated
- Dihydroergotamine intranasal + Erythromycin Contraindicated
- Dihydroergotamine + Erythromycin Contraindicated
- Domperidone + Erythromycin Contraindicated
- Dronedarone + Erythromycin Contraindicated
- Droperidol + Erythromycin Contraindicated
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 Erythromycin with Primaquine?
MediHelp rates the interaction as moderate. Erythromycin 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. Both drugs have been associated with QT prolongation, so combined use may increase the risk of ventricular arrhythmias including torsades de pointes. Risk is higher with electrolyte abnormalities or underlying heart disease.
How serious is the interaction between Erythromycin 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: Obtain a baseline ECG and correct hypokalemia and hypomagnesemia before starting. Consider a non-macrolide antibiotic in patients with other QT risk factors.
What other medicines interact with Erythromycin?
MediHelp also lists interactions of Erythromycin with, for example, Conivaptan, Dihydroergotamine intranasal, Dihydroergotamine. The full list is on the Erythromycin page.
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