Drug interactions
Clozapine + Loperamide
Severity: Major
Clozapine and Loperamide: major 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 clozapine also causes constipation and ileus, which opposes loperamide's use. Combination raises arrhythmia risk and may worsen gastrointestinal hypomotility.
What this interaction means in plain words
Clozapine and Loperamide can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for.
Clozapine belongs to Central Nervous System; Loperamide belongs to Gastrointestinal Tract.
Why it happens
Additive QT prolongation and additive reduction of gut motility.
What to do
Avoid unless essential and keep loperamide at the lowest dose for a short time. Monitor ECG, electrolytes and bowel function.
What to ask your pharmacist
- Does the benefit of taking both outweigh the risk in my case?
- Do I need any blood test, ECG or other check while on both?
- What early warning signs should I watch for, and what should I do if they appear?
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Other interactions of Loperamide
Other interactions of Clozapine
- Clozapine + Deferiprone Contraindicated
- Clozapine + Irinotecan Contraindicated
- Clozapine + Pimozide Contraindicated
- Clozapine + Thioridazine Contraindicated
- Acalabrutinib + Clozapine Major
- Adagrasib + Clozapine Major
Frequently asked questions
Can I take Clozapine with Loperamide?
MediHelp rates the interaction as major. Clozapine and Loperamide can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for. Both drugs can prolong the QT interval, and clozapine also causes constipation and ileus, which opposes loperamide's use. Combination raises arrhythmia risk and may worsen gastrointestinal hypomotility.
How serious is the interaction between Clozapine and Loperamide?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Avoid unless essential and keep loperamide at the lowest dose for a short time. Monitor ECG, electrolytes and bowel function.
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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