Lithium and Thiazide: Drug Interaction Guide
Quick answer: This is a major interaction — avoid combining Lithium and Thiazide unless specifically directed by your doctor.
How Lithium interacts with Thiazide
Thiazide diuretics reduce sodium reabsorption in distal tubule, triggering compensatory proximal tubule sodium and lithium reabsorption, increasing lithium levels by 25-40%.
What you should do
Reduce lithium dose by 25-50% before adding thiazide and recheck lithium level within 5-7 days. Monitor for tremor, confusion, polyuria as toxicity signs.
Key facts
Severity
Major — avoid combination
Mechanism
Thiazide diuretics reduce sodium reabsorption in distal tubule, triggering compensatory proximal tubule sodium and lithi...
Action
Reduce lithium dose by 25-50% before adding thiazide and recheck lithium level within 5-7 days. Monitor for tremor, conf...
Frequently asked questions
Can I take Lithium and Thiazide together?
No — this combination should generally be avoided. Reduce lithium dose by 25-50% before adding thiazide and recheck lithium level within 5-7 days. Monitor for tremor, confusion, polyuria as toxicity signs.
What is the severity of this interaction?
The interaction between Lithium and Thiazide is classified as Major — avoid combination. Thiazide diuretics reduce sodium reabsorption in distal tubule, triggering compensatory proximal tubule sodium and lithium reabsorption, increasing lithium levels by 25-40%.
What should I do if I'm prescribed both?
Reduce lithium dose by 25-50% before adding thiazide and recheck lithium level within 5-7 days. Monitor for tremor, confusion, polyuria as toxicity signs. Always consult your prescribing clinician — do not stop or change medications without medical guidance.
Last reviewed: by iMedic Medical Editorial Team. Our editorial process.