Impetigo Treatment with Trimethoprim-Sulfamethoxazole

Prescription Details

For a 19-month-old infant weighing 12.9 kg with impetigo, the American Academy of Pediatrics recommends a Bactrim dosage of 8-12 mg/kg/day (based on trimethoprim component) divided into two doses for 7 days 1
The medication should be Trimethoprim-Sulfamethoxazole (Bactrim) suspension (40 mg TMP/200 mg SMX per 5 mL), with a dosage of 2.5 mL twice daily for 7 days 2, 3
The total daily dose should be 5 mL (40 mg TMP/200 mg SMX per day) 2
The route of administration should be oral 1
The instructions are to give 2.5 mL by mouth twice daily for 7 days 2
The quantity should be 35 mL (sufficient for 7-day course) 1

The calculated dose of 8-12 mg/kg/day (based on trimethoprim component) provides appropriate coverage for skin and soft tissue infections, according to the Infectious Diseases Society of America 2, 1
For a 12.9 kg child, the daily dose of trimethoprim component is approximately 10 mg/kg/day, which falls within the recommended range 1

A 7-day course is appropriate for uncomplicated skin infections, as recommended by the American Academy of Pediatrics 1
Monitor for potential side effects, including gastrointestinal symptoms and rare but serious skin reactions 3

Parents should be advised to complete the full 7-day course even if symptoms improve earlier, as recommended by the American Academy of Pediatrics 1
Bactrim should be used with caution in infants under 2 months due to risk of kernicterus, but is safe for a 19-month-old 3
Ensure adequate hydration during treatment to prevent crystalluria 3

If the patient has a sulfa allergy or treatment failure occurs, alternative options include Cephalexin: 50-100 mg/kg/day divided in 4 doses, or Amoxicillin-clavulanate: 20-40 mg/kg/day in 3 doses, as recommended by the American Academy of Pediatrics 1