Drug interactions
Lithium + Saquinavir
Severity: Major
Lithium 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 can prolong the QT and PR intervals, and lithium may add to cardiac repolarization effects. Together they may increase the risk of arrhythmia, especially with boosted saquinavir regimens.
What this interaction means in plain words
Lithium 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 QTc prolongation.
What to do
Obtain a baseline ECG and monitor it, and correct potassium and magnesium. Consider an alternative antiretroviral 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?
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Other interactions of Lithium
- Lithium + Thioridazine Contraindicated
- Lithium + Vandetanib Contraindicated
- Aceclofenac + Lithium Major
- Acemetacin + Lithium Major
- Amisulpride + Lithium Major
- Amlodipine-benazepril + Lithium Major
Frequently asked questions
Can I take Lithium with Saquinavir?
MediHelp rates the interaction as major. Lithium 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 can prolong the QT and PR intervals, and lithium may add to cardiac repolarization effects. Together they may increase the risk of arrhythmia, especially with boosted saquinavir regimens.
How serious is the interaction between Lithium 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: Obtain a baseline ECG and monitor it, and correct potassium and magnesium. Consider an alternative antiretroviral if QTc becomes markedly prolonged.
What other medicines interact with Lithium?
MediHelp also lists interactions of Lithium with, for example, Thioridazine, Vandetanib, Aceclofenac. The full list is on the Lithium page.
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