Risperidone and Ranitidine Interaction
Drug interaction information between Risperidone and Ranitidine.
Risperidone and Ranitidine have a documented major interaction in FDA labeling.
FDA drug labeling documents a major-severity interaction between Risperidone and Ranitidine. 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
Ranitidine causes a small increase in risperidone levels, but it is not enough to change how the drug works or its safety.
What To Do
No dose adjustment is necessary when these two medications are used together.
FDA Label Information
Dose adjustment is not recommended for risperidone tablets when co-administered with ranitidine, cimetidine, amitriptyline, or erythromycin [see Table 18 ] . 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...
Risperidone Also Interacts With
- Amitriptyline major
- Carbamazepine major
- Lithium major
- Erythromycin major
- Cimetidine major
Ranitidine Also Interacts With
- Theophylline major
- Valproate major
- Midazolam moderate
- Clonazepam minor
- Darunavir minor
Frequently Asked Questions
Can I take Risperidone and Ranitidine together?
This is a major interaction. No dose adjustment is necessary when these two medications are used together.
How serious is the interaction between Risperidone and Ranitidine?
This interaction is classified as "major" severity by the FDA. Major interactions may be life-threatening or cause serious side effects.
Why do Risperidone and Ranitidine interact?
Ranitidine causes a small increase in risperidone levels, but it is not enough to change how the drug works or its safety.
Understanding the Risperidone and Ranitidine Interaction
FDA-approved prescribing information for these two drugs flags their combination as a major-severity interaction. Risperidone belongs to the Atypical Antipsychotic class and Ranitidine belongs to the H2 Receptor Antagonist class - two categories that can collide when co-prescribed. The mechanism described in FDA labeling is: Ranitidine causes a small increase in risperidone levels, but it is not enough to change how the drug works or its safety. 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. Risperidone has 20 total documented interactions on file in this dataset, and Ranitidine has 15. 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 adjustment is necessary when these two medications are used 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 Risperidone or Ranitidine 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.