Drug interactions
Lithium + Quinidine
Severity: Moderate
Lithium and Quinidine: moderate 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
Both agents have been associated with QT prolongation and arrhythmia, and lithium can cause sinus node dysfunction and T-wave changes. Combining them may increase the risk of ventricular arrhythmias, particularly with lithium toxicity or electrolyte disturbance.
What this interaction means in plain words
Lithium and Quinidine can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken.
Lithium belongs to Central Nervous System; Quinidine belongs to Anti Parasitic.
Why it happens
Additive effects on cardiac repolarization and conduction; the mechanism of lithium's QT effect is not well established.
What to do
Obtain a baseline ECG, monitor QTc and serum lithium levels, and correct potassium and magnesium. Avoid other QT-prolonging drugs.
What to ask your pharmacist
- Should I take them at different times of day?
- Does the dose of either medicine need to change?
- Is there anything I should avoid, such as alcohol or certain foods, while on both?
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Other interactions of Quinidine
- Adagrasib + Quinidine Contraindicated
- Arsenic trioxide + Quinidine Contraindicated
- Artemether / lumefantrine + Quinidine Contraindicated
- Chloroquine + Quinidine Contraindicated
- Dofetilide + Quinidine Contraindicated
- Dronedarone + Quinidine Contraindicated
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 Quinidine?
MediHelp rates the interaction as moderate. Lithium and Quinidine can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken. Both agents have been associated with QT prolongation and arrhythmia, and lithium can cause sinus node dysfunction and T-wave changes. Combining them may increase the risk of ventricular arrhythmias, particularly with lithium toxicity or electrolyte disturbance.
How serious is the interaction between Lithium and Quinidine?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Obtain a baseline ECG, monitor QTc and serum lithium levels, and correct potassium and magnesium. Avoid other QT-prolonging drugs.
What other medicines interact with Quinidine?
MediHelp also lists interactions of Quinidine with, for example, Adagrasib, Arsenic trioxide, Artemether / lumefantrine. The full list is on the Quinidine page.
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