What the FDA labels say about taking them together
Sepiapterin and trimethoprim
Sepiapterin's FDA label of April 24, 2026 names trimethoprim in its drug interactions section; the trimethoprim label PlainMeds reads does not name sepiapterin. The sepiapterin label: “DRUG INTERACTIONS Dihydrofolate Reductase (DHFR) Inhibitors: Avoid concomitant use. Sepiapterin Reductase (SR) Inhibitors:”
Check it at the source: the sepiapterin FDA label on DailyMed (effective April 24, 2026, PTC Therapeutics Inc.); the trimethoprim FDA label on DailyMed (effective January 26, 2024, Dr. Reddy's Labratories Inc.).
What does the sepiapterin label say about trimethoprim?
Sepiapterin label, drug interactionsDRUG INTERACTIONS Dihydrofolate Reductase (DHFR) Inhibitors: Avoid concomitant use (e.g., trimethoprim, methotrexate, trimetrexate, pemetrexed, pralatrexate, raltitrexed, or piritrexim). ( 7.1 ) Sepiapterin Reductase (SR) Inhibitors:
Source: FDA drug label (Sephience), PTC Therapeutics Inc., effective April 24, 2026 (SPL set 32ac719c-49f0-4105-9c46-18c19583a5c2), via openFDA; the full label on DailyMed
What does the trimethoprim label say about sepiapterin?
Trimethoprim's label (effective January 26, 2024) does not name sepiapterin in these sections. A label lists what its studies and reports found; it is not a complete list.
Source: FDA drug label (Trimethoprim), NDA018679 (Dr Reddys Labs Sa), as published by Dr. Reddy's Labratories Inc., effective January 26, 2024 (SPL set 73ccebc1-7412-2424-d62c-a5180ec52d81), 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
| Sepiapterin | Trimethoprim | |
|---|---|---|
| Labeled for | n/a | Bacterial infections, Urinary tract infections |
| Boxed warning | No | No |
| Pharmacy cost (NADAC) | n/a | $1.31 per tablet 100 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