What the FDA labels say about taking them together
Sulfamethoxazole/trimethoprim and valganciclovir
Valganciclovir's FDA label of December 8, 2025 names sulfamethoxazole/trimethoprim in its drug interactions section; the sulfamethoxazole/trimethoprim labels PlainMeds reads (2) do not name valganciclovir.
Check it at the source: the sulfamethoxazole/trimethoprim FDA label on DailyMed (effective December 30, 2024, Sun Pharmaceutical Industries, Inc); the valganciclovir FDA label on DailyMed (effective December 8, 2025, H2-Pharma, LLC).
What does the sulfamethoxazole/trimethoprim label say about valganciclovir?
Sulfamethoxazole/trimethoprim's label (effective December 30, 2024) and its 1 other brand-application label do 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 (Bactrim), Sun Pharmaceutical Industries, Inc, effective December 30, 2024 (SPL set f59d0c04-9c66-4d53-a0e1-cb55570deb62), via openFDA; the full label on DailyMed
What does the valganciclovir label say about sulfamethoxazole/trimethoprim?
Valganciclovir label, drug interactionsNamed in a table that the FDA label file prints without its column breaks; the full label shows the table.
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
| Sulfamethoxazole/trimethoprim | Valganciclovir | |
|---|---|---|
| Labeled for | Bacterial infections, Urinary tract infections, Diarrhea | n/a |
| Boxed warning | No | Yes |
| Pharmacy cost (NADAC) | $0.0448 per tablet Sulfamethoxazole-tmp ds tablet | $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