What the FDA labels say about taking them together
Atazanavir and ritonavir
Atazanavir's FDA label of August 6, 2025 names ritonavir in its contraindications section, and ritonavir's label names atazanavir too. The atazanavir label: “… surveillance in patients with HIV-1 treated with atazanavir, with or without ritonavir.”
Check it at the source: the atazanavir FDA label on DailyMed (effective August 6, 2025, Aurobindo Pharma Limited); the ritonavir FDA label on DailyMed (effective July 23, 2026, AbbVie Inc.).
What does the atazanavir label say about ritonavir?
Atazanavir label, contraindicationsDrug Class: Antiarrhythmics; Drugs within class that are contraindicated with atazanavir capsules: Amiodarone (with ritonavir), quinidine (with ritonavir)
Atazanavir label, drug interactionsUse of atazanavir without ritonavir is not recommended when coadministered with drugs highly dependent on CYP2C8 with narrow therapeutic indices (e.g., paclitaxel, repaglinide).
Atazanavir label, warnings and precautionsMonitor hepatic laboratory tests prior to therapy and during treatment. ( 2.8 , 5.4 , 8.8 ) Chronic kidney disease has been reported during postmarketing surveillance in patients with HIV-1 treated with atazanavir, with or without ritonavir.
Reyataz label (E.R. Squibb & Sons, L.L.C., December 5, 2024), warnings and precautionsThe concomitant use of REYATAZ with ritonavir and certain other medications may result in known or potentially significant drug interactions.
Source: FDA drug label (Reyataz, NDA021567), E.R. Squibb & Sons, L.L.C., effective December 5, 2024 (SPL set 165cff62-b284-4a27-a65d-9ec8a5bfcdd8), via openFDA
Source: FDA drug label (Atazanavir Sulfate), Aurobindo Pharma Limited, effective August 6, 2025 (SPL set 7fbea274-d6b5-4faa-bbf0-05fefab42114), via openFDA; the full label on DailyMed
What does the ritonavir label say about atazanavir?
Ritonavir label, drug interactionsConcomitant Drug Class/Drug Name: HIV-1 Protease Inhibitor: atazanavir darunavir fosamprenavir; Effect on Concentration of Ritonavir or Concomitant Drug: ↑ amprenavir ↑ atazanavir ↑ darunavir; Clinical Comment: See the complete prescribing information for fosamprenavir, atazanavir, darunavir for details on co-administration with ritonavir.
Ritonavir label, warnings and precautionsThe 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.
Source: FDA drug label (Norvir), AbbVie Inc., effective July 23, 2026 (SPL set 2849298e-de6e-47bb-8194-56e075b33fc3), via openFDA; the full label on DailyMed
These are the labels' own sentences. PlainMeds does not grade interactions; a pharmacist or prescriber can say what they mean for one person's medicines.
Both medicines on the record
| Atazanavir | Ritonavir | |
|---|---|---|
| Labeled for | HIV | HIV |
| Boxed warning | No | Yes |
| Pharmacy cost (NADAC) | $2.23 per capsule 300 mg capsule | $0.607 per tablet 100 mg tablet |
| Shortage now | No current entry | A presentation being discontinued |
Source: FDA NDC Directory, CMS NADAC of October 7, 2026 and the FDA Drug Shortage Database (FDA files October 8, 2026)
What next?
- Check more medicines together
- up to five at once