Drug interactions
Clarithromycin + Diltiazem
Severity: Moderate
Clarithromycin and Diltiazem: 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
Clarithromycin can increase diltiazem concentrations, causing hypotension, bradycardia, edema and in some cases acute kidney injury. Diltiazem itself inhibits CYP3A4 and may raise clarithromycin levels in return.
What this interaction means in plain words
Clarithromycin and Diltiazem 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.
Clarithromycin belongs to Anti Bacterial; Diltiazem belongs to Cardiovascular.
Why it happens
Clarithromycin inhibits CYP3A4-mediated diltiazem metabolism, and the two drugs have additive effects on heart rate and conduction.
What to do
Monitor blood pressure, heart rate and renal function, and reduce the diltiazem dose if needed. Consider azithromycin as an alternative, especially in older patients.
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 Clarithromycin and Diltiazem, 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 Clarithromycin
- Astemizole + Clarithromycin Contraindicated
- Avanafil + Clarithromycin Contraindicated
- Cisapride + Clarithromycin Contraindicated
- Clarithromycin + Colchicine Contraindicated
- Clarithromycin + Conivaptan Contraindicated
- Clarithromycin + Dihydroergotamine Contraindicated
Other interactions of Diltiazem
- Diltiazem + Flibanserin Contraindicated
- Diltiazem + Ivabradine Contraindicated
- Diltiazem + Lomitapide Contraindicated
- Diltiazem + Lonafarnib Contraindicated
- Acebutolol + Diltiazem Major
- Alfentanil + Diltiazem Major
Frequently asked questions
Can I take Clarithromycin with Diltiazem?
MediHelp rates the interaction as moderate. Clarithromycin and Diltiazem 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. Clarithromycin can increase diltiazem concentrations, causing hypotension, bradycardia, edema and in some cases acute kidney injury. Diltiazem itself inhibits CYP3A4 and may raise clarithromycin levels in return.
How serious is the interaction between Clarithromycin and Diltiazem?
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 pressure, heart rate and renal function, and reduce the diltiazem dose if needed. Consider azithromycin as an alternative, especially in older patients.
What other medicines interact with Clarithromycin?
MediHelp also lists interactions of Clarithromycin with, for example, Astemizole, Avanafil, Cisapride. The full list is on the Clarithromycin 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.
