Drug interactions
Atazanavir + Diltiazem
Severity: Major
Atazanavir and Diltiazem: major interaction.
Last updated Sources: US FDA label
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
Atazanavir increases diltiazem concentrations and may cause hypotension, bradycardia and AV block. Diltiazem may also raise atazanavir exposure and prolong the PR interval further.
What this interaction means in plain words
Atazanavir and Diltiazem can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for.
Atazanavir belongs to Anti Virals; Diltiazem belongs to Cardiovascular.
Why it happens
Atazanavir inhibits CYP3A4, reducing diltiazem metabolism; both drugs also prolong AV conduction.
What to do
Consider reducing the diltiazem dose by about half and monitor ECG and blood pressure. Avoid adding other PR-prolonging drugs.
What to ask your pharmacist
- Does the benefit of taking both outweigh the risk in my case?
- Do I need any blood test, ECG or other check while on both?
- What early warning signs should I watch for, and what should I do if they appear?
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References
Other interactions of Diltiazem
- Diltiazem + Flibanserin Contraindicated
- Diltiazem + Ivabradine Contraindicated
- Diltiazem + Lomitapide Contraindicated
- Diltiazem + Lonafarnib Contraindicated
- Acebutolol + Diltiazem Major
- Alfentanil + Diltiazem Major
Other interactions of Atazanavir
- Alfuzosin + Atazanavir Contraindicated
- Atazanavir + Avanafil Contraindicated
- Atazanavir + Dronedarone Contraindicated
- Atazanavir + Eletriptan Contraindicated
- Atazanavir + Eplerenone Contraindicated
- Atazanavir + Ergotamine Contraindicated
Frequently asked questions
Can I take Atazanavir with Diltiazem?
MediHelp rates the interaction as major. Atazanavir and Diltiazem can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for. Atazanavir increases diltiazem concentrations and may cause hypotension, bradycardia and AV block. Diltiazem may also raise atazanavir exposure and prolong the PR interval further.
How serious is the interaction between Atazanavir and Diltiazem?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Consider reducing the diltiazem dose by about half and monitor ECG and blood pressure. Avoid adding other PR-prolonging drugs.
What other medicines interact with Diltiazem?
MediHelp also lists interactions of Diltiazem with, for example, Flibanserin, Ivabradine, Lomitapide. The full list is on the Diltiazem page.
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