What the FDA labels say about taking them together
Etravirine and letermovir
Letermovir's FDA label of January 14, 2026 names etravirine in its drug interactions section; the etravirine label PlainMeds reads does not name letermovir. The letermovir label: “Co-administration of PREVYMIS and etravirine is not recommended due to potential for loss of efficacy of PREVYMIS.”
Check it at the source: the etravirine FDA label on DailyMed (effective August 15, 2023, Janssen Products LP); the letermovir FDA label on DailyMed (effective January 14, 2026, Merck Sharp & Dohme LLC).
What does the etravirine label say about letermovir?
Etravirine's label (effective August 15, 2023) does not name letermovir in these sections. A label lists what its studies and reports found; it is not a complete list.
Source: FDA drug label (Intelence), Janssen Products LP, effective August 15, 2023 (SPL set 6a9cbc29-9f15-4b24-8d86-206b82887f3d), via openFDA; the full label on DailyMed
What does the letermovir label say about etravirine?
Letermovir label, drug interactionsConcomitant Drug Class and/or Clearance Pathway/Drug Name: etravirine; Effect on Concentration ↓ =decrease, ↑ =increase: ↓ letermovir; Clinical Comments: Co-administration of PREVYMIS and etravirine is not recommended due to potential for loss of efficacy of PREVYMIS.
Source: FDA drug label (PREVYMIS), Merck Sharp & Dohme LLC, effective January 14, 2026 (SPL set 1b49df80-be4f-47e0-a0b7-123f3e69395b), 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
| Etravirine | Letermovir | |
|---|---|---|
| Labeled for | HIV | n/a |
| Boxed warning | No | No |
| Pharmacy cost (NADAC) | $9.94 per tablet 200 mg tablet | n/a |
| Shortage now | A presentation being discontinued | 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