Drug interactions
Cimetidine + Risperidone
Severity: Minor
Cimetidine and Risperidone: minor interaction.
Last updated
For healthcare professionals — reference only. This page is a brief summary, not medical advice and not a substitute for official labeling or clinical judgement. Always verify before prescribing or dispensing.
Summary
Cimetidine can modestly raise exposure to risperidone and its active metabolite. This may increase dose-related adverse effects such as sedation, orthostatic hypotension or extrapyramidal symptoms, although the effect is usually small.
What this interaction means in plain words
Cimetidine and Risperidone have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised.
Cimetidine belongs to Gastrointestinal Tract; Risperidone belongs to Central Nervous System.
Why it happens
Cimetidine weakly inhibits CYP2D6, which reduces the metabolism of risperidone to 9-hydroxyrisperidone.
What to do
No routine dose change is needed; watch for sedation, hypotension or extrapyramidal symptoms after cimetidine is started and reduce the risperidone dose if they emerge.
What to ask your pharmacist
- Is there anything I should notice while taking both?
- Do I need to tell my doctor at the next visit?
Pro+ members
Unlock the full page
Create an account and start a Pro+ trial to unlock the full management advice for Cimetidine and Risperidone, the additional notes, the evidence detail and the whole-prescription interaction checker.
- Full clinical management advice
- Additional notes
- Evidence detail
- Interaction checker for a whole prescription
Try Pro+ free for 7 days on the web. No card needed.
Other interactions of Cimetidine
- Cimetidine + Dofetilide Contraindicated
- Cimetidine + Fezolinetant Contraindicated
- Alfentanil + Cimetidine Major
- Atazanavir + Cimetidine Major
- Carmustine + Cimetidine Major
- Cimetidine + Citalopram Major
Other interactions of Risperidone
- Ibutilide + Risperidone Contraindicated
- Risperidone + Vandetanib Contraindicated
- Adagrasib + Risperidone Major
- Amiodarone + Risperidone Major
- Amisulpride + Risperidone Major
- Amoxapine + Risperidone Major
Frequently asked questions
Can I take Cimetidine with Risperidone?
MediHelp rates the interaction as minor. Cimetidine and Risperidone have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised. Cimetidine can modestly raise exposure to risperidone and its active metabolite. This may increase dose-related adverse effects such as sedation, orthostatic hypotension or extrapyramidal symptoms, although the effect is usually small.
How serious is the interaction between Cimetidine and Risperidone?
MediHelp rates it minor, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: No routine dose change is needed; watch for sedation, hypotension or extrapyramidal symptoms after cimetidine is started and reduce the risperidone dose if they emerge.
What other medicines interact with Cimetidine?
MediHelp also lists interactions of Cimetidine with, for example, Dofetilide, Fezolinetant, Alfentanil. The full list is on the Cimetidine page.
Full monographs, dosing and an interaction checker in the MediHelp app
Open the complete reference, check multi-drug interactions and use dosing tools in the MediHelp app.
