Trimethoprim Sulfamethoxazole
Bactrim is a brand-name antibiotic combining sulfamethoxazole and trimethoprim to treat various bacterial infections. It is commonly prescribed for urinary tract infections, ear infections, bronchitis, and traveler's diarrhea, among other conditions. This combination works synergistically to inhibit bacterial folate synthesis, making it effective against a broad range of gram-positive and gram-negative organisms.
A combination antibiotic used to treat bacterial infections like UTIs, ear infections, and bronchitis.
Key facts at a glance
- RxNorm
- 151399
- Generic
- Bactrim
- Class
- brand-name
- Brands
- —
- Availability
- rx
- Lactation
- unknown
- Routes
- —
- Forms
- —
- Regions
- US, EU, CN, JP
- Monitoring
- —
This page is for informational purposes only.
Do not use this information to diagnose yourself or to replace a physician's advice. Always consult a qualified healthcare provider before starting, stopping, or changing any medication. If you believe you are experiencing a medical emergency, call your local emergency number immediately.
Treats urinary tract infections, otitis media (ear infections), bronchitis, traveler's diarrhea, shigellosis, and Pneumocystis jirovecii pneumonia (PCP). May also be used for other susceptible bacterial infections as determined by a healthcare provider.
Combines two agents that work synergistically: sulfamethoxazole inhibits bacterial folate synthesis, while trimethoprim blocks a subsequent step in the pathway. Together, they provide bactericidal activity against susceptible organisms.
Not suitable for patients with sulfa drug allergies or severe kidney impairment. Common side effects include nausea, vomiting, skin rash, and photosensitivity. Can cause elevated potassium levels and may interact with blood thinners and certain heart medications. Complete the full course as prescribed; do not stop early even if symptoms improve. Avoid excessive sun exposure during treatment.
Official drug label
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This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed September 3, 2026. · Read our editorial policy