Drug interactions
Loperamide + Primaquine
Severity: Moderate
Loperamide 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
Primaquine has been associated with QT prolongation, and high-dose loperamide can have the same effect. Combined use may increase the risk of arrhythmia.
What this interaction means in plain words
Loperamide 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.
Loperamide belongs to Gastrointestinal Tract; Primaquine belongs to Anti Parasitic.
Why it happens
Additive QT prolongation through cardiac repolarization effects.
What to do
Keep loperamide at labeled doses and check an ECG in patients with cardiac risk factors. Correct potassium and magnesium abnormalities.
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 Loperamide
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 Loperamide with Primaquine?
MediHelp rates the interaction as moderate. Loperamide 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. Primaquine has been associated with QT prolongation, and high-dose loperamide can have the same effect. Combined use may increase the risk of arrhythmia.
How serious is the interaction between Loperamide 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: Keep loperamide at labeled doses and check an ECG in patients with cardiac risk factors. Correct potassium and magnesium abnormalities.
What other medicines interact with Loperamide?
MediHelp also lists interactions of Loperamide with, for example, Amiodarone, Amisulpride, Anagrelide. The full list is on the Loperamide page.
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