Drug interactions
Cimetidine + Olaparib
Severity: Moderate
Cimetidine and Olaparib: moderate 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
Olaparib is metabolised by CYP3A4. Cimetidine is only a weak inhibitor, so the increase in olaparib exposure is modest, with potential for more myelosuppression and nausea.
What this interaction means in plain words
Cimetidine and Olaparib can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken.
Cimetidine belongs to Gastrointestinal Tract; Olaparib belongs to Oncology.
Why it happens
Weak CYP3A4 inhibition by cimetidine reduces olaparib clearance.
What to do
Monitor blood counts and gastrointestinal tolerability; no routine dose reduction is needed as for moderate or strong inhibitors.
What to ask your pharmacist
- Should I take them at different times of day?
- Does the dose of either medicine need to change?
- Is there anything I should avoid, such as alcohol or certain foods, while on both?
Pro+ members
Unlock the full page
Create an account and start a Pro+ trial to unlock the full management advice for Cimetidine and Olaparib, 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 Olaparib
- Amiodarone + Olaparib Major
- Amobarbital + Olaparib Major
- Apalutamide + Olaparib Major
- Aprepitant + Olaparib Major
- Azathioprine + Olaparib Major
- Carbamazepine + Olaparib Major
Frequently asked questions
Can I take Cimetidine with Olaparib?
MediHelp rates the interaction as moderate. Cimetidine and Olaparib can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken. Olaparib is metabolised by CYP3A4. Cimetidine is only a weak inhibitor, so the increase in olaparib exposure is modest, with potential for more myelosuppression and nausea.
How serious is the interaction between Cimetidine and Olaparib?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Monitor blood counts and gastrointestinal tolerability; no routine dose reduction is needed as for moderate or strong inhibitors.
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.
