MedeliX
Start asking

Trimethoprim

Motrim, Triprim · ATC code J01EA01

Also known as: Trimetoprim

Key facts
Active substance
Trimethoprim
ATC code
J01EA01
Authorisation
authorised nationally; no central EU authorisation
Information as of
2026-10-29

Key facts

Trimethoprim is an antibacterial drug. Per the US prescribing information, it is used for initial episodes of uncomplicated urinary tract infections caused by susceptible organisms.

What it is used for

  • Initial episodes of uncomplicated urinary tract infections due to susceptible strains of Escherichia coli, Proteus mirabilis, Klebsiella pneumoniae, Enterobacter species and coagulase-negative Staphylococcus species including S. saprophyticus
  • Only for infections proven or strongly suspected to be bacterial

Dosing

  • Adults: 100 mg every 12 hours or 200 mg every 24 hours, each for 10 days
  • Creatinine clearance 15 to 30 mL/min: 50 mg every 12 hours
  • Creatinine clearance below 15 mL/min: not recommended

Contraindications

  • Hypersensitivity to trimethoprim
  • Documented megaloblastic anemia due to folate deficiency

Important warnings

  • Rare serious hypersensitivity reactions
  • Rarely interferes with hematopoiesis, especially with large doses or prolonged use; sore throat, fever, pallor or purpura may be early signs, then check blood counts
  • Clostridium difficile-associated diarrhea, even over two months after treatment
  • Caution in impaired renal or hepatic function

Side effects

  • Most often rash and pruritus; rash incidence 2.9% to 6.7% at recommended doses
  • Epigastric distress, nausea, vomiting, glossitis; elevated transaminases and bilirubin
  • Thrombocytopenia, leukopenia, neutropenia, megaloblastic anemia, methemoglobinemia; hyperkalemia, hyponatremia
  • Rarely exfoliative dermatitis, Stevens-Johnson syndrome, toxic epidermal necrolysis, anaphylaxis, aseptic meningitis

Interactions

  • Phenytoin: half-life increased by 51%; watch for excessive phenytoin effect
  • May interfere with the methotrexate assay (CBPA) and the Jaffe creatinine assay

Pregnancy and breastfeeding

  • Teratogenic in rats; no adequate studies in pregnant women; use only if the benefit justifies the risk
  • Excreted in human milk and may interfere with folic acid metabolism; use caution when nursing

Summary of the official product information, written with AI on 2026-10-29. Every number was checked automatically against the original text. Not reviewed by a physician – the full official text is authoritative.

Full official text →

Common questions – ask Medelix

For patients

Patient information (US)

This product has no separate US patient information.

Authorisation and brand names by country

Medicines with exactly this active-substance composition, as listed in the national registers – alphabetical and without ranking. Whether a product is currently available is not shown here.

Austria

  • MotrimG.L. Pharma Gmbh · 1 register entry
  • TriprimTeva B.V · 1 register entry

Source: EMA – Article 57 product data (EU/EEA), as of 2026-10-29

Germany

  • InfectotrimetInfectopharm Arzneimittel Und Consilium Gmbh, De, Heppenheim · 1 register entry

Source: EMA – Article 57 product data (EU/EEA), as of 2026-10-29

Brand names in 13 more European countries
Denmark
Trimopan
Estonia
Trimetop
Finland
Trimetin, Trimopan
France
Delprim
Iceland
Idotrim, Trimetoprim Viatris
Ireland
Monotrim, Trimethoprim Athlone Pharmaceuticals, Trimoptin
Latvia
Trimetop
Lithuania
Trimetop
Netherlands
Trimethoprim Cf, Trimethoprim Mylan
Norway
Trimetoprim Orion
Poland
Trimesan, Urotrim
Spain
Tediprima
Sweden
Idotrim, Trimetoprim Viatris

EMA – Article 57 product data (EU/EEA), 2026-10-29

Medelix receives no money from pharmaceutical companies. Brand names are listed alphabetically and without ranking.

Related calculators

Another question about this substance?

Medelix answers clinical questions from guidelines, studies and product information – every claim with its source.

Sources

  1. U.S. Food and Drug Administration. Trimethoprim (Lupin Pharmaceuticals,Inc.) – Prescribing Information, 2024-06-04. DailyMed (NLM), 2026-10-29. https://dailymed.nlm.nih.gov/dailymed/lookup.cfm?setid=249e938d-f181-47c4-a082-372d65462f33
  2. EMA – Article 57 product data (EU/EEA), 2026-10-29. https://www.ema.europa.eu/en/human-regulatory-overview/post-authorisation/data-medicines-iso-idmp-standards-post-authorisation/public-data-article-57-database
  3. EMA – Article 57 product data (EU/EEA), 2026-10-29. https://www.ema.europa.eu/en/human-regulatory-overview/post-authorisation/data-medicines-iso-idmp-standards-post-authorisation/public-data-article-57-database

Editorial: Medelix editorial team · last updated 2026-10-29 · How these pages are made · Report an error

Source: U.S. Food and Drug Administration (FDA), prescribing information, via DailyMed (NLM); public domain. Not advertising, not a treatment recommendation. For questions about your own treatment, ask your doctor or pharmacist.