Atazanavir and Ritonavir interaction
Atazanavir and Ritonavir: both prescribing labels flag this combination with the strongest language, such as a contraindication, a boxed warning, or an instruction to avoid it.
Do not combine without a prescriber's guidance. The label language below is the strongest FDA uses.
What the FDA labels say
From the Atazanavir (REYATAZ) label · effective 2024-12-05
…contraindicated with, but not limited to, the following drugs listed in Table 6: Table 6: Drugs Contraindicated with REYATAZ (Information in the table applies to REYATAZ with or without ritonavir, unless otherwise indicated) a See Drug Interactions, Table 16 (7) for parenterally administered midazolam. b See Drug Interactions, Table 16 (7) for sildenafil when dosed…
…within class that are contraindicated with REYATAZ Alpha 1-adrenoreceptor antagonist Alfuzosin Anticonvulsants Carbamazepine, phenobarbital, phenytoin Antiarrhythmics Amiodarone (with ritonavir), quinidine (with ritonavir) Antimycobacterials Rifampin Antineoplastics Apalutamide, encorafenib, irinotecan, ivosidenib Antipsychotics Lurasidone (with ritonavir), pimozide…
Use of REYATAZ without ritonavir is not recommended when coadministered with drugs highly dependent on CYP2C8 with narrow therapeutic indices (eg, paclitaxel, repaglinide).
Antiarrhythmics: amiodarone, quinidine amiodarone, bepridil, lidocaine (systemic), quinidine ↑ amiodarone, bepridil, lidocaine (systemic), quinidine Concomitant use of REYATAZ with ritonavir and either quinidine or amiodarone is contraindicated due to the potential for serious or life-threatening reactions such as cardiac arrhythmias [see Contraindications (4)…
Coadministration with REYATAZ without ritonavir has the potential to produce serious and/or life-threatening adverse events but has not been studied.
From the Ritonavir (Norvir) label · effective 2026-07-23
The impact on the PR interval of co-administration of ritonavir with other drugs that prolong the PR interval (including calcium channel blockers, beta-adrenergic blockers, digoxin and atazanavir) has not been evaluated.
When co-administering NORVIR with other protease inhibitors, see the full prescribing information for that protease inhibitor including important Warnings and Precautions.
Hepatotoxicity Hepatic transaminase elevations exceeding 5 times the upper limit of normal, clinical hepatitis, and jaundice have occurred in patients receiving NORVIR alone or in combination with other antiretroviral drugs (see Table 2).
Continued administration of ritonavir 600 mg twice daily following loss of viral suppression may increase the likelihood of cross-resistance to other protease inhibitors [see Microbiology ( 12.4 ) ] .
Titrate atorvastatin and rosuvastatin dose carefully and use the lowest necessary dose.If NORVIR is used with another protease inhibitor, see the complete prescribing information for the concomitant protease inhibitor for details on co-administration with atorvastatin and rosuvastatin.
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Open in the checkerNot medical advice. Interaction Checker quotes FDA label text and NIH fact sheets. Whether an interaction matters for you depends on doses, timing, kidney and liver function, and other conditions. Confirm with a pharmacist or prescriber.