What the FDA labels say about taking them together
Atazanavir and tenofovir disoproxil
Atazanavir's FDA label of August 6, 2025 names tenofovir disoproxil in its drug interactions section, and tenofovir disoproxil's label names atazanavir too. The atazanavir label: “When coadministered with tenofovir DF in adults, it is recommended that REYATAZ 300 mg be given with ritonavir 100 mg and tenofovir DF 300 mg. The mechanism of this interaction is unknown. …”
Check it at the source: the atazanavir FDA label on DailyMed (effective August 6, 2025, Aurobindo Pharma Limited); the tenofovir disoproxil FDA label on DailyMed (effective June 7, 2024, Aurobindo Pharma Limited).
What does the atazanavir label say about tenofovir disoproxil?
Atazanavir label, drug interactionsConcomitant Drug Class/Specific Drugs: Nucleotide Reverse Transcriptase Inhibitors: tenofovir disoproxil fumarate (DF); Effect on Concentration of Atazanavir or Concomitant Drug: ↓ atazanavir ↑ tenofovir; Clinical Comment: When coadministered with tenofovir DF in adults, it is recommended that atazanavir 300 mg be given with ritonavir 100 mg and tenofovir DF 300 mg (all as a single daily dose with food). The mechanism of this interaction is unknown. Higher tenofovir concentrations could potentiate tenofovir-associated adverse reactions, including renal disorders. Patients receiving atazanavir and tenofovir DF should be monitored for tenofovir-associated adverse reactions. …
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 tenofovir disoproxil label say about atazanavir?
Tenofovir disoproxil label, drug interactionsDose reduction and close monitoring for didanosine toxicity are warranted. ( 7.2 ) Coadministration decreases atazanavir concentrations.
Source: FDA drug label (Tenofovir Disoproxil Fumarate), Aurobindo Pharma Limited, effective June 7, 2024 (SPL set a75c6be8-3719-4bb3-8a9e-06e5254d2a82), 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 | Tenofovir disoproxil | |
|---|---|---|
| Labeled for | HIV | HIV, Hepatitis B |
| Boxed warning | No | Yes |
| Pharmacy cost (NADAC) | $2.23 per capsule 300 mg capsule | $0.294 per tablet 300 mg tablet |
| Shortage now | No current entry | No current entry |
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