Drug interactions
Haloperidol + Saquinavir
Severity: Major
Haloperidol and Saquinavir: 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
Saquinavir (usually boosted with ritonavir) prolongs QT and inhibits CYP3A4, which can raise haloperidol concentrations. The combination increases the risk of torsades de pointes and other serious arrhythmias.
What this interaction means in plain words
Haloperidol and Saquinavir 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.
Why it happens
Additive QT prolongation with CYP3A4 inhibition reducing haloperidol clearance.
What to do
Avoid the combination where possible and choose an alternative antipsychotic or antiretroviral. If unavoidable, monitor ECG and electrolytes and use the lowest effective haloperidol dose.
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 Haloperidol
- Dofetilide + Haloperidol Contraindicated
- Dronedarone + Haloperidol Contraindicated
- Haloperidol + Ibutilide Contraindicated
- Haloperidol + Levoketoconazole Contraindicated
- Haloperidol + Panobinostat Contraindicated
- Haloperidol + Pimozide Contraindicated
Frequently asked questions
Can I take Haloperidol with Saquinavir?
MediHelp rates the interaction as major. Haloperidol and Saquinavir 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. Saquinavir (usually boosted with ritonavir) prolongs QT and inhibits CYP3A4, which can raise haloperidol concentrations. The combination increases the risk of torsades de pointes and other serious arrhythmias.
How serious is the interaction between Haloperidol and Saquinavir?
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 where possible and choose an alternative antipsychotic or antiretroviral. If unavoidable, monitor ECG and electrolytes and use the lowest effective haloperidol dose.
What other medicines interact with Haloperidol?
MediHelp also lists interactions of Haloperidol with, for example, Dofetilide, Dronedarone, Ibutilide. The full list is on the Haloperidol page.
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