Trimethoprim-Sulfamethoxazole (TMP-SMX) Alternative Names
Trimethoprim-sulfamethoxazole (TMP-SMX) is commonly known as co-trimoxazole, Bactrim, or Sulfatrim. 1, 2
Official Names and Composition
TMP-SMX is a synthetic antibacterial combination product consisting of two active ingredients:
- Trimethoprim (TMP): 2,4-diamino-5-(3,4,5-trimethoxybenzyl)pyrimidine
- Sulfamethoxazole (SMX): N1-(5-methyl-3-isoxazolyl) sulfanilamide 1, 2
The medication is available in several formulations:
- Double strength (DS) tablets: 800 mg sulfamethoxazole + 160 mg trimethoprim
- Regular strength tablets: 400 mg sulfamethoxazole + 80 mg trimethoprim
- Pediatric suspension (Sulfatrim Pediatric): Dosed based on body surface area 3
Common Brand Names
While the question specifically asks for alternative names, it's important to note that TMP-SMX is marketed under several brand names worldwide:
- Bactrim
- Septra
- Sulfatrim (particularly for pediatric formulations) 3
- Co-trimoxazole (international non-proprietary name)
Clinical Context
TMP-SMX is widely used in clinical practice for:
- Pneumocystis jirovecii pneumonia (PJP, formerly PCP) prophylaxis and treatment in immunocompromised patients 4
- Treatment of various bacterial infections including:
Important Considerations
When prescribing TMP-SMX, be aware that:
Hypersensitivity reactions are more common in HIV-positive patients (up to 60%) compared to HIV-negative patients (about 5%) 4
The medication is contraindicated in:
- Patients with known hypersensitivity to trimethoprim or sulfonamides
- Infants younger than 2 months due to risk of kernicterus
- Patients with severe renal impairment (creatinine clearance <15 mL/min) 3
Dosage adjustments are required for patients with renal impairment (creatinine clearance 15-30 mL/min) 3
In summary, TMP-SMX is a widely used antibiotic combination known by several names including co-trimoxazole, Bactrim, and Sulfatrim, with specific formulations tailored for different patient populations and clinical scenarios.