What the FDA labels say about taking them together
Flucytosine and valganciclovir
Valganciclovir's FDA label of December 8, 2025 names flucytosine in its drug interactions section; the flucytosine label PlainMeds reads does not name valganciclovir. The valganciclovir label: “Because of potential for higher toxicity, coadministration with VALCYTE should be considered only if the potential benefits are judged to outweigh the risks.”
Check it at the source: the flucytosine FDA label on DailyMed (effective February 2, 2022, Bausch Health US LLC); the valganciclovir FDA label on DailyMed (effective December 8, 2025, H2-Pharma, LLC).
What does the flucytosine label say about valganciclovir?
Flucytosine's label (effective February 2, 2022) does not name valganciclovir in these sections. A label lists what its studies and reports found; it is not a complete list.
Source: FDA drug label (ANCOBON), Bausch Health US LLC, effective February 2, 2022 (SPL set aea0df00-a88c-4a16-abcf-750f3ff2004e), via openFDA; the full label on DailyMed
What does the valganciclovir label say about flucytosine?
Valganciclovir label, drug interactionsName of the Concomitant Drug: Other drugs associated with myelosuppression or nephrotoxicity (e.g., adriamycin, dapsone, doxorubicin, flucytosine, hydroxyurea, pentamidine, tacrolimus, trimethoprim/ sulfamethoxazole, vinblastine, vincristine, and zidovudine); Change in the Concentration of Ganciclovir or Concomitant Drug: Unknown; Clinical Comment: Because of potential for higher toxicity, coadministration with VALCYTE should be considered only if the potential benefits are judged to outweigh the risks.
Source: FDA drug label (Valcyte), NDA021304 (Cheplapharm), as published by H2-Pharma, LLC, effective December 8, 2025 (SPL set 4c517a39-2ded-4c5a-8d56-276853414b31), 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
| Flucytosine | Valganciclovir | |
|---|---|---|
| Labeled for | Fungal infections | n/a |
| Boxed warning | Yes | Yes |
| Pharmacy cost (NADAC) | n/a | $1.91 per tablet 450 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