Lithium and Risperidone Interaction
Drug interaction information between Lithium and Risperidone.
Lithium and Risperidone have a documented major interaction in FDA labeling.
FDA drug labeling documents a major-severity interaction between Lithium and Risperidone. 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
Taking risperidone does not change the amount of lithium that stays in your bloodstream or how your body handles it.
What To Do
No dose changes are necessary for lithium when it is used at the same time as risperidone.
FDA Label Information
Do not exceed twice the patient’s usual dose Enzyme (CYP3A) inhibitors Ranitidine 150 mg twice daily 1 mg single dose 1.2 1.4 Dose adjustment not needed Cimetidine 400 mg twice daily 1 mg single dose 1.1 1.3 Dose adjustment not needed Erythromycin 500 mg four times daily 1 mg single dose 1.1 0.94 Dose adjustment not needed Other Drugs Amitriptyline 50 mg twice daily 3 mg twice daily 1.2 1.1 Dose adjustment not Needed *Change relative to reference Effect of Risperidone on other drugs Lithium Repeated oral doses of risperidone tablets (3 mg twice daily) did not affect the exposure (AUC) or...
Lithium Also Interacts With
- Amlodipine/Benazepril major
- Amiloride moderate
- Amiodarone moderate
- Amlodipine/Valsartan moderate
- Azilsartan moderate
Risperidone Also Interacts With
- Amitriptyline major
- Carbamazepine major
- Erythromycin major
- Ranitidine major
- Cimetidine major
Frequently Asked Questions
Can I take Lithium and Risperidone together?
This is a major interaction. No dose changes are necessary for lithium when it is used at the same time as risperidone.
How serious is the interaction between Lithium and Risperidone?
This interaction is classified as "major" severity by the FDA. Major interactions may be life-threatening or cause serious side effects.
Why do Lithium and Risperidone interact?
Taking risperidone does not change the amount of lithium that stays in your bloodstream or how your body handles it.
Understanding the Lithium and Risperidone Interaction
FDA-approved prescribing information for these two drugs flags their combination as a major-severity interaction. Lithium belongs to the Mood Stabilizer class and Risperidone belongs to the Atypical Antipsychotic class - two categories that can collide when co-prescribed. The mechanism described in FDA labeling is: Taking risperidone does not change the amount of lithium that stays in your bloodstream or how your body handles it. 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. Lithium has 90 total documented interactions on file in this dataset, and Risperidone has 20. 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: No dose changes are necessary for lithium when it is used at the same time as risperidone. 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 Lithium or Risperidone 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.