What the FDA labels say about taking them together
Efavirenz and elbasvir/grazoprevir
Efavirenz's FDA label of March 31, 2024 names elbasvir/grazoprevir in its drug interactions section, and elbasvir/grazoprevir's label names efavirenz too. The elbasvir/grazoprevir label: “Co-administration of ZEPATIER with strong CYP3A inducers or efavirenz is contraindicated.”
Check it at the source: the efavirenz FDA label on DailyMed (effective March 31, 2024, Cipla USA Inc.); the elbasvir/grazoprevir FDA label on DailyMed (effective March 13, 2026, Merck Sharp & Dohme LLC).
What does the efavirenz label say about elbasvir/grazoprevir?
Efavirenz label, drug interactionsElbasvir/Grazoprevir ↓ elbasvir ↓ grazoprevir Coadministration of efavirenz with elbasvir/grazoprevir is contraindicated [see Contraindications ( 4 )] because it may lead to loss of virologic response to elbasvir/grazoprevir.
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 elbasvir/grazoprevir label say about efavirenz?
Elbasvir/grazoprevir label, contraindicationsNamed in a table that the FDA label file prints without its column breaks; the full label shows the table.
Elbasvir/grazoprevir label, drug interactionsCo-administration of ZEPATIER with strong CYP3A inducers or efavirenz is contraindicated [see Contraindications (4), Clinical Pharmacology (12.3), and Table 2 ].
Source: FDA drug label (ZEPATIER), Merck Sharp & Dohme LLC, effective March 13, 2026 (SPL set 164dc02a-9180-426a-b8b5-04ab39d2bbd4), 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 | Elbasvir/grazoprevir | |
|---|---|---|
| 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 | 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