What the FDA labels say about taking them together
Efavirenz and emtricitabine
Efavirenz's FDA label of March 31, 2024 names emtricitabine in its drug interactions section; the emtricitabine label PlainMeds reads does 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 emtricitabine FDA label on DailyMed (effective December 2, 2025, Gilead Sciences, Inc.).
What does the efavirenz label say about emtricitabine?
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 emtricitabine label say about efavirenz?
Emtricitabine's label (effective December 2, 2025) does 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 (Emtriva), Gilead Sciences, Inc., effective December 2, 2025 (SPL set d6599395-3944-44f9-97f2-e0424c6b6a1f), 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 | Emtricitabine | |
|---|---|---|
| Labeled for | HIV | HIV |
| Boxed warning | No | Yes |
| Pharmacy cost (NADAC) | $1.28 per tablet 600 mg tablet | $12.69 per capsule 200 mg capsule |
| 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