Cotrimoxazole (TMP-SMX)
Brand: Bactrim (US/EU) / Septran (IN) / Cotrim (BD)
Antibiotic
Folate pathway inhibitor combo (TMP+SMX)
Chemistry
Structure
Pharmacokinetics
| Half-life | 10 hours |
| Tmax | 2 h |
| Bioavailability | 90 % (approx) |
| Protein Binding | 45 % |
| Volume of Distribution | 1.6 L/kg (approx) |
| Clearance Route | mixed |
| Active Metabolites | no |
| Notes | Calculator uses trimethoprim mg (e.g., DS 800/160 → 160 mg). Adjust dose in renal impairment. |
⚠️ Safety & Warnings
Severity: Severe
Adverse Effects:
Rash (SJS/TEN rare), hyperkalemia, bone marrow suppression, photosensitivity
Contraindications:
Sulfa allergy, severe hepatic failure
Precautions:
Check K+ especially with ACEi/ARB; CBC if prolonged high-dose; dose adjust in CKD