What the FDA labels say about taking them together
Mycophenolate mofetil and sulfamethoxazole/trimethoprim
Mycophenolate mofetil's FDA label of August 5, 2026 names sulfamethoxazole/trimethoprim in its drug interactions section; the sulfamethoxazole/trimethoprim labels PlainMeds reads (2) do not name mycophenolate mofetil. The mycophenolate mofetil label: “Examples Cyclosporine A, trimethoprim/sulfamethoxazole, bile acid sequestrants (cholestyramine), rifampin as well as aminoglycoside, cephalosporin, fluoroquinolone and penicillin classes of antimicrobials Drugs …”
Check it at the source: the mycophenolate mofetil FDA label on DailyMed (effective August 5, 2026, Genentech, Inc.); the sulfamethoxazole/trimethoprim FDA label on DailyMed (effective December 30, 2024, Sun Pharmaceutical Industries, Inc).
What does the mycophenolate mofetil label say about sulfamethoxazole/trimethoprim?
Mycophenolate mofetil label, drug interactionsExamples Cyclosporine A, trimethoprim/sulfamethoxazole, bile acid sequestrants (cholestyramine), rifampin as well as aminoglycoside, cephalosporin, fluoroquinolone and penicillin classes of antimicrobials Drugs Modulating Glucuronidation Clinical Impact Concomitant use with drugs inducing glucuronidation decreases MPA systemic exposure, potentially reducing CELLCEPT efficacy, while use with drugs inhibiting glucuronidation increases MPA systemic exposure [see Clinical Pharmacology (12.3) ], which may increase the risk of CELLCEPT related adverse reactions. …
Source: FDA drug label (CellCept), NDA050722 (Roche Palo), as published by Genentech, Inc., effective August 5, 2026 (SPL set 37241e87-4af4-4dc3-a1aa-ea6f20d8dc40), via openFDA; the full label on DailyMed
What does the sulfamethoxazole/trimethoprim label say about mycophenolate mofetil?
Sulfamethoxazole/trimethoprim's label (effective December 30, 2024) and its 1 other brand-application label do not name mycophenolate mofetil 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
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
| Mycophenolate mofetil | Sulfamethoxazole/trimethoprim | |
|---|---|---|
| Labeled for | Organ transplant rejection | Bacterial infections, Urinary tract infections, Diarrhea |
| Boxed warning | Yes | No |
| Pharmacy cost (NADAC) | $0.138 per capsule 250 mg capsule | $0.0448 per tablet Sulfamethoxazole-tmp ds 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