What the FDA labels say about taking them together
Cyclosporine and letermovir
Letermovir's FDA label of January 14, 2026 names cyclosporine in its contraindications section; the cyclosporine labels PlainMeds reads (4) do not name letermovir. The letermovir label: “When PREVYMIS is co-administered with glyburide, repaglinide, or rosiglitazone, frequently monitor glucose concentrations. When PREVYMIS is co-administered with cyclosporine, use of repaglinide is not recommended.”
Check it at the source: the cyclosporine FDA label on DailyMed (effective August 10, 2026, Novartis Pharmaceuticals Corporation); the letermovir FDA label on DailyMed (effective January 14, 2026, Merck Sharp & Dohme LLC).
What does the cyclosporine label say about letermovir?
Cyclosporine's label (effective August 10, 2026) and its 3 other brand-application labels do 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 (Neoral), Novartis Pharmaceuticals Corporation, effective August 10, 2026 (SPL set 94461af3-11f1-4670-95d4-2965b9538ae3), via openFDA; the full label on DailyMed
What does the letermovir label say about cyclosporine?
Letermovir label, contraindicationsPREVYMIS is contraindicated with pitavastatin and simvastatin when co-administered with cyclosporine.
Letermovir label, drug interactionsConcomitant Drug Class and/or Clearance Pathway/Drug Name: Examples: glyburide, repaglinide, rosiglitazone; Effect on Concentration ↓ =decrease, ↑ =increase: ↑ glyburide ↑ repaglinide ↑ rosiglitazone; Clinical Comments: When PREVYMIS is co-administered with glyburide, repaglinide, or rosiglitazone, frequently monitor glucose concentrations. When PREVYMIS is co-administered with cyclosporine, use of repaglinide is not recommended.
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
| Cyclosporine | Letermovir | |
|---|---|---|
| Labeled for | Organ transplant rejection, Rheumatoid arthritis | n/a |
| Boxed warning | Yes | No |
| Pharmacy cost (NADAC) | $1.04 per unit 0.05% eye emulsion | 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