Risperidone and Cimetidine Interaction
Drug interaction information between Risperidone and Cimetidine.
Risperidone and Cimetidine have a documented major interaction in FDA labeling.
FDA drug labeling documents a major-severity interaction between Risperidone and Cimetidine. This page displays the available source-record category and label text. The category is not an individual risk estimate or medication-combination direction.
How They Interact
Cimetidine can slightly slow down the enzymes that break down risperidone, but the effect is very small.
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
- Ranitidine major
Cimetidine Also Interacts With
- Levofloxacin major
- Posaconazole major
- Valproate major
- Empagliflozin moderate
- Empagliflozin/Linagliptin moderate
Frequently Asked Questions
What SPL severity band is on file for Risperidone + Cimetidine?
Compiled FDA labeling labels this pair major. That is a source-record field, not an individual medication-combination decision.
Which drug in this pair has the larger labeled-interaction portfolio?
Cimetidine has 77 labeled pairs on file vs Risperidone's 20. In the major band specifically: Risperidone has 6 (also Amitriptyline, Carbamazepine, Lithium, Erythromycin); Cimetidine has 4 (also Levofloxacin, Posaconazole, Valproate).
What mechanism field is on file for Risperidone and Cimetidine?
Cimetidine can slightly slow down the enzymes that break down risperidone, but the effect is very small.
Risperidone carries more major-labeled pairs than Cimetidine
SPL source-record counts only. This page's band is major · classes on file: Risperidone (Atypical Antipsychotic); Cimetidine (H2 Receptor Antagonist).
Risperidone has 6 major-labeled pairs vs Cimetidine's 4.
6 major · 5 moderate · 9 minor · 20 total
- Other major peers for Risperidone
- Amitriptyline
- Carbamazepine
- Lithium
- Erythromycin
4 major · 10 moderate · 63 minor · 77 total
- Other major peers for Cimetidine
- Levofloxacin
- Posaconazole
- Valproate
Sources: FDA Drug Labels (SPL) via openFDA (2026). This is for informational purposes only and is not medical advice. This registry does not provide individual medication-combination directions.
Read our methodology - how this data is sourced, computed, and verified.