Drug interactions
Granisetron + Loperamide
Severity: Moderate
Granisetron 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
Both drugs can prolong the QT interval, and high-dose or misused loperamide has been linked to torsades de pointes and cardiac arrest. Together they may raise the risk of ventricular arrhythmia, particularly in patients with other risk factors.
What this interaction means in plain words
Granisetron 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.
Granisetron belongs to Gastrointestinal Tract; Loperamide belongs to Gastrointestinal Tract.
Why it happens
Additive QT prolongation through cardiac potassium channel (hERG) blockade.
What to do
Use standard loperamide doses only and avoid exceeding the labeled maximum. Obtain an ECG and correct potassium and magnesium in patients with additional 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 Loperamide
Other interactions of Granisetron
- Apomorphine + Granisetron Contraindicated
- Amiodarone + Granisetron Major
- Amisulpride + Granisetron Major
- Arsenic trioxide + Granisetron Major
- Artemether / lumefantrine + Granisetron Major
- Artemether + Granisetron Major
Frequently asked questions
Can I take Granisetron with Loperamide?
MediHelp rates the interaction as moderate. Granisetron 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. Both drugs can prolong the QT interval, and high-dose or misused loperamide has been linked to torsades de pointes and cardiac arrest. Together they may raise the risk of ventricular arrhythmia, particularly in patients with other risk factors.
How serious is the interaction between Granisetron 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 standard loperamide doses only and avoid exceeding the labeled maximum. Obtain an ECG and correct potassium and magnesium in patients with additional QT risk factors.
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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