Losartan and Lithium Interaction
Drug interaction information between Losartan and Lithium.
Losartan and Lithium have a documented moderate interaction in FDA labeling.
FDA drug labeling documents a moderate-severity interaction between Losartan and Lithium. Major interactions are generally avoided, moderate ones may need monitoring or a dose adjustment, and minor ones are usually low-risk. This page shows the documented mechanism and guidance. Label-documented interactions are not a complete safety review, so always confirm your own medications with a pharmacist or doctor. Educational information, not medical advice.
How They Interact
Losartan can make it harder for your body to get rid of lithium. This can cause lithium to build up to dangerous levels in your blood.
What To Do
Your doctor should monitor your lithium blood levels closely while you take these drugs together. Watch for signs of too much lithium, like tremors or feeling very thirsty.
FDA Label Information
(7.1) • Lithium: Risk of lithium toxicity. 7.2 Lithium Increases in serum lithium concentrations and lithium toxicity have been reported during concomitant administration of lithium with angiotensin II receptor antagonists. Monitor serum lithium levels during concomitant use.
Losartan Also Interacts With
- Aliskiren major
- Fluconazole minor
- Glecaprevir/Pibrentasvir minor
- Hydrochlorothiazide minor
- Hydrochlorothiazide/Lisinopril minor
Lithium Also Interacts With
- Amlodipine/Benazepril major
- Risperidone major
- Amiloride moderate
- Amiodarone moderate
- Amlodipine/Valsartan moderate
Frequently Asked Questions
Can I take Losartan and Lithium together?
This is a moderate interaction. Your doctor should monitor your lithium blood levels closely while you take these drugs together. Watch for signs of too much lithium, like tremors or feeling very thirsty.
How serious is the interaction between Losartan and Lithium?
This interaction is classified as "moderate" severity by the FDA. Moderate interactions may worsen your condition or change how your medications work.
Why do Losartan and Lithium interact?
Losartan can make it harder for your body to get rid of lithium. This can cause lithium to build up to dangerous levels in your blood.
Understanding the Losartan and Lithium Interaction
FDA-approved prescribing information for these two drugs flags their combination as a moderate-severity interaction. Losartan belongs to the Angiotensin II Receptor Blocker (ARB) class and Lithium belongs to the Mood Stabilizer class - two categories that can collide when co-prescribed. The mechanism described in FDA labeling is: Losartan can make it harder for your body to get rid of lithium. Severity tiers matter: major flags generally advise avoidance, moderate flags often require monitoring or dose adjustment, and minor flags may only call for awareness.
Context around a specific patient determines real-world impact. Losartan has 10 total documented interactions on file in this dataset, and Lithium has 90. Each additional medication compounds the interaction surface, which is why pharmacists run full-profile checks rather than evaluating one pair at a time. FDA-derived guidance for this pair is: Your doctor should monitor your lithium blood levels closely while you take these drugs together. Timing of doses, renal and hepatic function, age, and other concurrent prescriptions all shape whether a labeled interaction matters clinically.
An interaction flag is not a verdict. A large share of labeled interactions are managed routinely in clinical practice, the fix may be as simple as spacing doses or adding a monitoring test. Others require the prescriber to choose a different medication entirely. This page surfaces FDA-sourced labeling and openFDA data for educational purposes only; it is not medical advice and cannot account for your full clinical picture. Never start, stop, or adjust either Losartan or Lithium based on a web page, speak with your prescriber or pharmacist before making any change.
Sources: FDA Drug Labels (SPL) via openFDA (2026). This is for informational purposes only and is not medical advice. Always consult your healthcare provider about drug interactions.
Read our methodology - how this data is sourced, computed, and verified.