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Drug interactions

Erythromycin ethylsuccinate + Loperamide

Severity: Moderate

Erythromycin ethylsuccinate and Loperamide: 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

Erythromycin inhibits P-gp and CYP3A4 and can increase loperamide concentrations. Erythromycin also prolongs the QT interval, so the combination raises the risk of cardiac toxicity.

What this interaction means in plain words

Erythromycin ethylsuccinate and Loperamide 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.

Evidence level: Moderate

Why it happens

Inhibition of P-gp and CYP3A4 by erythromycin raises loperamide exposure, with additive QT effects.

What to do

Use loperamide at the lowest effective dose and avoid exceeding labeled limits. Monitor for palpitations, syncope and CNS depression, and check electrolytes if risk factors are present.

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?

Bring a full list of your medicines, including over-the-counter products, supplements and herbal remedies, to every pharmacy visit.

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Frequently asked questions

Can I take Erythromycin ethylsuccinate with Loperamide?

MediHelp rates the interaction as moderate. Erythromycin ethylsuccinate and Loperamide 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 inhibits P-gp and CYP3A4 and can increase loperamide concentrations. Erythromycin also prolongs the QT interval, so the combination raises the risk of cardiac toxicity.

How serious is the interaction between Erythromycin ethylsuccinate and Loperamide?

MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Use loperamide at the lowest effective dose and avoid exceeding labeled limits. Monitor for palpitations, syncope and CNS depression, and check electrolytes if risk factors are present.

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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