Pediatric Dosage of Sulfaprim (Trimethoprim/Sulfamethoxazole)

Dosage by Age and Weight

The American Academy of Pediatrics recommends a dosage of 8-12 mg/kg/day of trimethoprim and 40-60 mg/kg/day of sulfamethoxazole for children over 2 months, divided into 2 doses every 12 hours 1, 2
Children under 2 months should not be given Sulfaprim due to the risk of kernicterus, as recommended by the Centers for Disease Control and Prevention 3

The Infectious Diseases Society of America recommends a dosage of 8-12 mg/kg/day (based on trimethoprim) for 7-10 days for skin and soft tissue infections 2, 4

The Centers for Disease Control and Prevention recommend monitoring patients with hemogram tests at the start of treatment and monthly to evaluate hematological toxicity 5

The Centers for Disease Control and Prevention state that Sulfaprim is contraindicated in children under 2 months and in patients with known hypersensitivity to sulfonamides or trimethoprim 3
The Centers for Disease Control and Prevention recommend caution in patients with renal insufficiency, hepatic insufficiency, and G6PD deficiency, and recommend monitoring for hematological toxicity 5, 6

The Centers for Disease Control and Prevention report that Sulfaprim can cause dermatological reactions, hematological alterations, gastrointestinal effects, and an increased risk of hemolytic anemia in patients with G6PD deficiency 3, 6

The American Academy of Dermatology recommends caution when using Sulfaprim with metotrexate, as it may increase toxicity, and also recommends caution with anticoagulants, hypoglycemics, thiazide diuretics, and anticonvulsants 3, 7

The World Health Organization recommends 4 mg/kg trimethoprim (20 mg/kg sulfamethoxazole) twice daily for 5 days for urinary tract infections in children over 2 months of age 8

The Centers for Disease Control and Prevention recommends obtaining a complete blood count with differential and platelet count at treatment initiation and repeating it monthly during prolonged therapy to assess for hematologic toxicity including neutropenia, thrombocytopenia, and anemia 9

Adverse reactions occur in approximately 15% of HIV-infected children, with common effects including dermatologic reactions such as rash, hematologic effects like neutropenia and thrombocytopenia, gastrointestinal complaints, hepatic effects like hepatitis, and renal effects like interstitial nephritis, according to the Centers for Disease Control and Prevention 9
The Centers for Disease Control and Prevention advises that for mild rash, treatment should be temporarily discontinued and restarted when resolved, while for urticarial rash or Stevens-Johnson syndrome, treatment should be permanently discontinued 9

The Centers for Disease Control and Prevention recommends 8 mg/kg/day trimethoprim (40 mg/kg/day sulfamethoxazole) for 14 days for all household and close contacts for Pertussis Prophylaxis 10