Methyldopa and Lithium Interaction
Drug interaction information between Methyldopa and Lithium.
Methyldopa and Lithium have a documented minor interaction in FDA labeling.
FDA drug labeling documents a minor-severity interaction between Methyldopa 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
Methyldopa can cause lithium to build up in the body to levels that are not safe.
What To Do
Your doctor should monitor you closely for any signs of lithium toxicity.
FDA Label Information
When methyldopa and lithium are given concomitantly, the patient should be carefully monitored for symptoms of lithium toxicity. Read the circular for lithium preparations.
Methyldopa Also Interacts With
- Ferrous Sulfate moderate
- Carbidopa/Levodopa moderate
- Tranylcypromine moderate
- Colestipol minor
- Enalapril minor
Lithium Also Interacts With
- Amlodipine/Benazepril major
- Risperidone major
- Amiloride moderate
- Amiodarone moderate
- Amlodipine/Valsartan moderate
Frequently Asked Questions
Can I take Methyldopa and Lithium together?
This is a minor interaction. Your doctor should monitor you closely for any signs of lithium toxicity.
How serious is the interaction between Methyldopa and Lithium?
This interaction is classified as "minor" severity by the FDA. Minor interactions are unlikely to cause significant problems but should still be mentioned to your healthcare provider.
Why do Methyldopa and Lithium interact?
Methyldopa can cause lithium to build up in the body to levels that are not safe.
Understanding the Methyldopa and Lithium Interaction
FDA-approved prescribing information for these two drugs flags their combination as a minor-severity interaction. Methyldopa belongs to the Central Alpha-2 Agonist class and Lithium belongs to the Mood Stabilizer class - two categories that can collide when co-prescribed. The mechanism described in FDA labeling is: Methyldopa can cause lithium to build up in the body to levels that are not safe. 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. Methyldopa has 7 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 you closely for any signs of lithium toxicity. 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 Methyldopa 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.