Drug interactions
Fostemsavir + Pimozide
Severity: Major
Fostemsavir and Pimozide: 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
Fostemsavir has caused QT prolongation at supratherapeutic doses, and pimozide is a strongly QT-prolonging drug with a narrow margin of safety. Combined use may increase the risk of torsades de pointes, particularly with other risk factors.
What this interaction means in plain words
Fostemsavir and Pimozide 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.
Fostemsavir belongs to Anti Virals; Pimozide belongs to Central Nervous System.
Why it happens
Additive QT-interval prolongation through cardiac repolarization effects.
What to do
Obtain a baseline ECG and monitor QTc and electrolytes if the combination cannot be avoided. Correct potassium and magnesium abnormalities, and choose an alternative if QTc becomes markedly prolonged.
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?
Pro+ members
Unlock the full page
Create an account and start a Pro+ trial to unlock the full management advice for Fostemsavir and Pimozide, the additional notes, the evidence detail and the whole-prescription interaction checker.
- Full clinical management advice
- Additional notes
- Evidence detail
- Interaction checker for a whole prescription
Try Pro+ free for 14 days on the web. No card needed.
Other interactions of Pimozide
- Adagrasib + Pimozide Contraindicated
- Amiodarone + Pimozide Contraindicated
- Amisulpride + Pimozide Contraindicated
- Amitriptyline + Pimozide Contraindicated
- Amoxapine + Pimozide Contraindicated
- Anagrelide + Pimozide Contraindicated
Other interactions of Fostemsavir
- Apalutamide + Fostemsavir Contraindicated
- Carbamazepine + Fostemsavir Contraindicated
- Enzalutamide + Fostemsavir Contraindicated
- Fostemsavir + Mitotane Contraindicated
- Fostemsavir + Phenytoin Contraindicated
- Fostemsavir + Rifampicin Contraindicated
Frequently asked questions
Can I take Fostemsavir with Pimozide?
MediHelp rates the interaction as major. Fostemsavir and Pimozide 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. Fostemsavir has caused QT prolongation at supratherapeutic doses, and pimozide is a strongly QT-prolonging drug with a narrow margin of safety. Combined use may increase the risk of torsades de pointes, particularly with other risk factors.
How serious is the interaction between Fostemsavir and Pimozide?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Obtain a baseline ECG and monitor QTc and electrolytes if the combination cannot be avoided. Correct potassium and magnesium abnormalities, and choose an alternative if QTc becomes markedly prolonged.
What other medicines interact with Pimozide?
MediHelp also lists interactions of Pimozide with, for example, Adagrasib, Amiodarone, Amisulpride. The full list is on the Pimozide page.
Full monographs, dosing and an interaction checker in the MediHelp app
Open the complete reference, check multi-drug interactions and use dosing tools in the MediHelp app.
