What the FDA labels say about taking them together
Efavirenz/emtricitabine/tenofovir disoproxil and lamivudine
Efavirenz/emtricitabine/tenofovir disoproxil's FDA label of July 28, 2025 names lamivudine in its warnings and precautions section; the lamivudine labels PlainMeds reads (2) do not name efavirenz/emtricitabine/tenofovir disoproxil. The efavirenz/emtricitabine/tenofovir disoproxil label: “When psychiatric symptoms similar to those noted above were combined and evaluated as a group in a multifactorial analysis of data from Study AI266006 (006, NCT00002410), a Phase 3 randomized, open-label trial of …”
Check it at the source: the efavirenz/emtricitabine/tenofovir disoproxil FDA label on DailyMed (effective July 28, 2025, Laurus Labs Limited); the lamivudine FDA label on DailyMed (effective January 5, 2026, Strides Pharma Science Limited).
What does the efavirenz/emtricitabine/tenofovir disoproxil label say about lamivudine?
Efavirenz/emtricitabine/tenofovir disoproxil label, warnings and precautionsWhen psychiatric symptoms similar to those noted above were combined and evaluated as a group in a multifactorial analysis of data from Study AI266006 (006, NCT00002410), a Phase 3 randomized, open-label trial of EFV-containing regimens versus controls in 1,266 subjects (median follow-up 180 weeks, 102 weeks, and 76 weeks for subjects treated with EFV + zidovudine + lamivudine, EFV + indinavir, and indinavir + zidovudine + lamivudine, respectively), treatment with EFV was associated with an increase in the occurrence of these selected psychiatric symptoms.
Source: FDA drug label (Efavirenz, emtricitabine and tenofovir disoproxil fumarate), Laurus Labs Limited, effective July 28, 2025 (SPL set aca22076-f435-4533-9fcf-566b0734c313), via openFDA; the full label on DailyMed
What does the lamivudine label say about efavirenz/emtricitabine/tenofovir disoproxil?
Lamivudine's label (effective January 5, 2026) and its 1 other brand-application label do not name efavirenz/emtricitabine/tenofovir disoproxil in these sections. A label lists what its studies and reports found; it is not a complete list.
Source: FDA drug label (Lamivudine), Strides Pharma Science Limited, effective January 5, 2026 (SPL set ac824c7e-9c9f-487b-ad2f-d50eaef5cbda), 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/tenofovir disoproxil | Lamivudine | |
|---|---|---|
| Labeled for | HIV | HIV, Hepatitis B |
| Boxed warning | Yes | Yes |
| Pharmacy cost (NADAC) | $1.12 per tablet 600-200-300 mg tablet | $0.489 per tablet 150 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