What the FDA labels say about taking them together
Efavirenz and sofosbuvir/velpatasvir/voxilaprevir
Efavirenz's FDA label of March 31, 2024 names sofosbuvir/velpatasvir/voxilaprevir in its drug interactions section, and sofosbuvir/velpatasvir/voxilaprevir's label names efavirenz too. The sofosbuvir/velpatasvir/voxilaprevir label: “Coadministration of VOSEVI with efavirenz-containing regimens is not recommended.”
Check it at the source: the efavirenz FDA label on DailyMed (effective March 31, 2024, Cipla USA Inc.); the sofosbuvir/velpatasvir/voxilaprevir FDA label on DailyMed (effective July 14, 2025, Gilead Sciences, Inc.).
What does the efavirenz label say about sofosbuvir/velpatasvir/voxilaprevir?
Efavirenz label, drug interactionsVelpatasvir /Sofosbuvir/ Voxilaprevir ↓ velpatasvir ↓ voxilaprevir Coadministration of efavirenz and sofosbuvir/velpatasvir/voxilaprevir is not recommended because it may result in loss of therapeutic effect of sofosbuvir/velpatasvir/voxilaprevir Other agents Anticoagulant:Warfarin ↑ or ↓ warfarin Monitor international normalised ratio (INR) and adjust warfarin dosage if necessary.
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 sofosbuvir/velpatasvir/voxilaprevir label say about efavirenz?
Sofosbuvir/velpatasvir/voxilaprevir label, drug interactionsConcomitant Drug Class/Drug Name: efavirenz; Effect on Concentration ↓ = decrease, ↑ = increase.: ↓ velpatasvir ↓ voxilaprevir; Clinical Effect/Recommendation: Coadministration of VOSEVI with efavirenz-containing regimens is not recommended.
Source: FDA drug label (Vosevi), Gilead Sciences, Inc., effective July 14, 2025 (SPL set 17ffc094-8ca7-45d2-80d8-fd043bc9a221), 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 | Sofosbuvir/velpatasvir/voxilaprevir | |
|---|---|---|
| Labeled for | HIV | Hepatitis C |
| Boxed warning | No | Yes |
| Pharmacy cost (NADAC) | $1.28 per tablet 600 mg tablet | n/a |
| 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