What the FDA labels say about taking them together
Efavirenz and tenofovir disoproxil
Efavirenz's FDA label of March 31, 2024 names tenofovir disoproxil in its drug interactions section; the tenofovir disoproxil labels PlainMeds reads (2) do not name efavirenz. The efavirenz label: “Interactions with Efavirenz No dosage adjustment is recommended when efavirenz is given with the following: aluminum/magnesium hydroxide antacids, azithromycin, cetirizine, famotidine, fluconazole, lorazepam …”
Check it at the source: the efavirenz FDA label on DailyMed (effective March 31, 2024, Cipla USA Inc.); the tenofovir disoproxil FDA label on DailyMed (effective June 7, 2024, Aurobindo Pharma Limited).
What does the efavirenz label say about tenofovir disoproxil?
Efavirenz label, drug interactionsInteractions with Efavirenz No dosage adjustment is recommended when efavirenz is given with the following: aluminum/magnesium hydroxide antacids, azithromycin, cetirizine, famotidine, fluconazole, lorazepam, nelfinavir, nucleoside reverse transcriptase inhibitors (abacavir, emtricitabine, lamivudine, stavudine, tenofovir disoproxil fumarate, zidovudine), paroxetine, and raltegravir.
Efavirenz label, warnings and precautionsConsider potential for cross-resistance when choosing other agents. ( 5.3 ) Not recommended with ATRIPLA, which contains efavirenz, emtricitabine, and tenofovir disoproxil fumarate, unless needed for dose adjustment when coadministered with rifampin. ( 5.4 ) Serious psychiatric symptoms:
Source: FDA drug label (Efavirenz), Cipla USA Inc., effective March 31, 2024 (SPL set 92603fa5-7a2c-4bfb-9a70-aadb4fba952c), via openFDA; the full label on DailyMed
What does the tenofovir disoproxil label say about efavirenz?
Tenofovir disoproxil's label (effective June 7, 2024) and its 1 other brand-application label do not name efavirenz in these sections. A label lists what its studies and reports found; it is not a complete list.
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
| Efavirenz | Tenofovir disoproxil | |
|---|---|---|
| Labeled for | HIV | HIV, Hepatitis B |
| Boxed warning | No | Yes |
| Pharmacy cost (NADAC) | $1.28 per tablet 600 mg tablet | $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