What the FDA labels say about taking them together
Letermovir and pimozide
Letermovir's FDA label of January 14, 2026 names pimozide in its contraindications section; the pimozide label PlainMeds reads does not name letermovir. The letermovir label: “Co-administration is contraindicated due to risk of QT prolongation and torsades de pointes.”
Check it at the source: the letermovir FDA label on DailyMed (effective January 14, 2026, Merck Sharp & Dohme LLC); the pimozide FDA label on DailyMed (effective August 12, 2026, Par Health USA, LLC).
What does the letermovir label say about pimozide?
Letermovir label, contraindicationsCONTRAINDICATIONS PREVYMIS is contraindicated in patients receiving pimozide or ergot alkaloids:
Letermovir label, drug interactionsConcomitant Drug Class and/or Clearance Pathway/Drug Name: pimozide; Effect on Concentration ↓ =decrease, ↑ =increase: ↑ pimozide; Clinical Comments: Co-administration is contraindicated due to risk of QT prolongation and torsades de pointes [see ].
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
What does the pimozide label say about letermovir?
Pimozide's label (effective August 12, 2026) 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 (Pimozide), Par Health USA, LLC, effective August 12, 2026 (SPL set 70b079e2-a1f7-4a93-8685-d60a4d7c1280), 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
| Letermovir | Pimozide | |
|---|---|---|
| Labeled for | n/a | n/a |
| Boxed warning | No | No |
| Pharmacy cost (NADAC) | n/a | $1.23 per tablet 1 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