Drug interactions
Pimavanserin + Saquinavir
Severity: Major
Pimavanserin 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 inhibits CYP3A4 and increases pimavanserin concentrations, and both drugs prolong the QT interval, so the arrhythmia risk is increased through two routes.
What this interaction means in plain words
Pimavanserin 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
CYP3A4 inhibition raises pimavanserin exposure, with additive QTc prolongation.
What to do
Reduce pimavanserin to 10 mg daily if coadministered and monitor ECG; consider an alternative antiretroviral since saquinavir itself carries QT warnings.
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 Pimavanserin
- Lefamulin + Pimavanserin Contraindicated
- Pimavanserin + Pimozide Contraindicated
- Pimavanserin + Vandetanib Contraindicated
- Adagrasib + Pimavanserin Major
- Amiodarone + Pimavanserin Major
- Amisulpride + Pimavanserin Major
Frequently asked questions
Can I take Pimavanserin with Saquinavir?
MediHelp rates the interaction as major. Pimavanserin 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 inhibits CYP3A4 and increases pimavanserin concentrations, and both drugs prolong the QT interval, so the arrhythmia risk is increased through two routes.
How serious is the interaction between Pimavanserin 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: Reduce pimavanserin to 10 mg daily if coadministered and monitor ECG; consider an alternative antiretroviral since saquinavir itself carries QT warnings.
What other medicines interact with Pimavanserin?
MediHelp also lists interactions of Pimavanserin with, for example, Lefamulin, Pimozide, Vandetanib. The full list is on the Pimavanserin page.
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