Chemical Formula of Cotrimoxazole:
- Sulfamethoxazole (SMX): C₁₀H₁₁N₃O₃S
- Trimethoprim (TMP): C₁₄H₁₈N₄O₃
Mechanism of Action:
A synergistic combination that inhibits folate synthesis:
- SMX: Blocks dihydropteroate synthase.
- TMP: Inhibits dihydrofolate reductase (DHFR).
- Together, they cause a bactericidal
Uses of Cotrimoxazole:
- UTIs: coli, Klebsiella, Enterobacter
- Respiratory infections: Pneumocystis jirovecii pneumonia, bronchitis.
- GI infections: Traveler’s diarrhea, shigellosis, typhoid.
- Skin infections: MRSA, nocardiosis, toxoplasmosis (immunocompromised).
Side Effects:
- Hypersensitivity: Rash, Stevens-Johnson syndrome.
- Hematologic toxicity: Anemia, leukopenia.
- Renal issues: Crystalluria, nephrotoxicity.
- Electrolyte imbalance:
- Neonatal risk:
