Drug interactions
Atazanavir + Fentanyl
Severity: Major
Atazanavir and Fentanyl: 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 is a potent CYP3A4 inhibitor and can markedly raise fentanyl exposure. This may lead to profound sedation and life-threatening respiratory depression, particularly with transmucosal or other non-titrated dosing.
What this interaction means in plain words
Atazanavir and Fentanyl 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; Fentanyl belongs to Musculoskeletal.
Why it happens
Inhibition of CYP3A4-mediated fentanyl metabolism in the liver and gut wall reduces clearance and raises plasma concentrations.
What to do
Avoid the combination where possible; if unavoidable, reduce the fentanyl dose and monitor frequently for sedation and respiratory depression. Re-evaluate the dose when atazanavir is started or stopped.
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 Fentanyl
- Alvimopan + Fentanyl Contraindicated
- Fentanyl + Isocarboxazid Contraindicated
- Fentanyl + Olanzapine / samidorphan Contraindicated
- Fentanyl + Phenelzine Contraindicated
- Fentanyl + Tranylcypromine Contraindicated
- Alfentanil + Fentanyl 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 Fentanyl?
MediHelp rates the interaction as major. Atazanavir and Fentanyl 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 is a potent CYP3A4 inhibitor and can markedly raise fentanyl exposure. This may lead to profound sedation and life-threatening respiratory depression, particularly with transmucosal or other non-titrated dosing.
How serious is the interaction between Atazanavir and Fentanyl?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Avoid the combination where possible; if unavoidable, reduce the fentanyl dose and monitor frequently for sedation and respiratory depression. Re-evaluate the dose when atazanavir is started or stopped.
What other medicines interact with Fentanyl?
MediHelp also lists interactions of Fentanyl with, for example, Alvimopan, Isocarboxazid, Olanzapine / samidorphan. The full list is on the Fentanyl page.
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