Drug interactions
Clozapine + Pentamidine
Severity: Major
Clozapine and Pentamidine: major interaction.
Last updated Sources: US FDA label
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 systemic pentamidine has been linked to torsades de pointes. Combined use increases the risk of severe arrhythmia, and pentamidine may also cause hypoglycemia or electrolyte disturbance and neutropenia.
What this interaction means in plain words
Clozapine and Pentamidine 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; Pentamidine belongs to Anti Parasitic.
Why it happens
Additive QTc prolongation.
What to do
Avoid the combination when an alternative exists. If used, obtain a baseline ECG, correct electrolytes and monitor QTc and blood counts.
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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References
Other interactions of Clozapine
- Clozapine + Deferiprone Contraindicated
- Clozapine + Irinotecan Contraindicated
- Clozapine + Pimozide Contraindicated
- Clozapine + Thioridazine Contraindicated
- Acalabrutinib + Clozapine Major
- Adagrasib + Clozapine Major
Other interactions of Pentamidine
- Clomipramine + Pentamidine Contraindicated
- Desipramine + Pentamidine Contraindicated
- Dronedarone + Pentamidine Contraindicated
- Moxifloxacin + Pentamidine Contraindicated
- Nortriptyline + Pentamidine Contraindicated
- Pentamidine + Pimozide Contraindicated
Frequently asked questions
Can I take Clozapine with Pentamidine?
MediHelp rates the interaction as major. Clozapine and Pentamidine 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 systemic pentamidine has been linked to torsades de pointes. Combined use increases the risk of severe arrhythmia, and pentamidine may also cause hypoglycemia or electrolyte disturbance and neutropenia.
How serious is the interaction between Clozapine and Pentamidine?
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 the combination when an alternative exists. If used, obtain a baseline ECG, correct electrolytes and monitor QTc and blood counts.
What other medicines interact with Clozapine?
MediHelp also lists interactions of Clozapine with, for example, Deferiprone, Irinotecan, Pimozide. The full list is on the Clozapine page.
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