General Information


  • NOT for IM injection
  • Infuse IV over 60-90 minutes
  • PO dosing with or without food, with at least 8 oz. water


  • Dilute well with D5W in 1:15-1:25 ratio (5mL solution diluted in 75-125mL base solution)
  • Use 1:15 ratio for fluid restricted patients


  • D5W
  • Urinary tract infections
  • Susceptible MRSA infections
  • Stenotrophomonas infections
  • Pneumocystis jirovecii pneumonia (Treatment or prophylaxis)

Tier 1 Protected Antimicrobial

  • Narrow spectrum, possible transition for discharge, IV to PO
  • Strategy: Total EBM duration set (inpatient and outpatient)
  • Follow SCr/BUN for renal injury
  • Electrolytes in patients at increased risk renal failure
  • Monitor for hyperkalemia
  • CBC
  • Liver function at baseline
  • Gastrointestinal upset common
  • Bone marrow suppression
  • Hyperkalemia
  • Renal failure
  • Hepatitis
  • Aseptic meningitis
  • Stevens Johnson syndrome/toxic epidermal necrolysis
  • Other rashes
  • ACEi - Increased serum potassium level
  • Increases amantadine levels
  • Decreases cyclosporine
  • Methotrexate - Marrow suppression
  • Increases phenytoin
  • Increases rifampin
  • Increases INR with warfarin
  • Increases dofetilide concentrations
  • Metronidazole causes disulfuram-like reactions with IV Bactrim

Antimicrobial class: Sulfonamide - Antifolate

Pregnancy category: C

Average serum half life: 10 hours

Urine penetration: Therapeutic

Lung penetration: Therapeutic

CSF penetration: Therapeutic

Biliary penetration: Moderate

Bactrim, Bactrim-DS