Trimethoprim/Sulfamethoxazole is Bactrim
Yes, trimethoprim/sulfamethoxazole is the same as Bactrim. Bactrim is simply a brand name for the combination antibiotic containing trimethoprim and sulfamethoxazole 1.
Details About Trimethoprim/Sulfamethoxazole
Trimethoprim/sulfamethoxazole (TMP-SMX) is available under several brand names:
- Bactrim (manufactured by Roche Laboratories) 2
- Septra (manufactured by GlaxoSmithKline) 2
- Also available as generic cotrimoxazole 2
Chemical Composition
The medication consists of two active ingredients:
- Trimethoprim: 2,4-diamino-5-(3,4,5-trimethoxybenzyl) pyrimidine
- Sulfamethoxazole: N1-(5-methyl-3-isoxazolyl) sulfanilamide 1
Available Formulations
TMP-SMX is available in multiple formulations:
- Oral tablets (regular and double strength)
- Oral suspension (pediatric formulation)
- Intravenous solution 3, 4
Standard Dosing
- Adult standard dose: 160 mg trimethoprim/800 mg sulfamethoxazole (double strength) twice daily 3
- Pediatric dosing: Based on trimethoprim component, typically 8-12 mg/kg/day divided into two doses 3
Clinical Applications
TMP-SMX is FDA-approved for treating:
- Urinary tract infections 2, 5
- Otitis media (ear infections) 3
- Shigellosis 3
- Pneumocystis jirovecii pneumonia (treatment and prophylaxis) 3, 4
It's also commonly used off-label for:
- Skin and soft tissue infections 6
- Respiratory tract infections 6, 7
- Bacterial exacerbations of chronic bronchitis 7
- Nocardia asteroides infections 4
Important Considerations
Efficacy
TMP-SMX works through sequential blockade in the biosynthesis of tetrahydrofolic acid, with the combination providing greater antimicrobial activity than either agent alone 8.
Resistance Concerns
The Infectious Diseases Society of America notes that rising rates of TMP-SMX resistance among uropathogens has impacted its use as a first-line agent for urinary tract infections in some regions 2.
Adverse Effects
Common adverse effects include:
Rare but serious adverse effects include:
Contraindications
TMP-SMX is contraindicated in:
- Patients with known hypersensitivity to trimethoprim or sulfonamides
- Infants younger than 2 months
- Patients with severe renal impairment (creatinine clearance <15 mL/min) 3
In summary, Bactrim is indeed a brand name for the antibiotic combination trimethoprim/sulfamethoxazole, which is widely used to treat various bacterial infections.