Age and findings	Therapy
Younger than one month	Ampicillin plus gentamicin  Ampicillin,* 100 to 200 mg per kg per day IM or IV, divided, every six hours  Gentamicin,† 2.5 mg per kg IM or IV every eight hours, with adjustments based on serum levels Alternative: Ampicillin plus cefotaxime (Claforan)  Ampicillin,* 100 to 200 mg per kg per day IM or IV, divided, every six hours  Cefotaxime,* 150 to 200 mg per kg per day IM or IV, divided, every six to eight hours Alternative: Cefotaxime alone, 150 to 200 mg per kg per day IM or IV, divided, every six to eight hours* If Streptococcus pneumoniae meningitis is suspected, add vancomycin, 20 mg per kg IV loading dose, then check creatinine levels:  < 0.7 mg per dL, use 15 mg per kg every 12 hours  0.7 to 0.9, use 20 mg per kg every 24 hours  1.0 to 1.2, use 15 mg per kg every 24 hours  1.3 to 1.6, use 10 mg per kg every 24 hours  > 1.6, use 15 mg per kg every 48 hours
One to three months, meningitis not suspected	Ceftriaxone (Rocephin), 50 to 75 mg per kg per day IM or IV, divided, every 12 to 24 hours Alternative: Cefotaxime, 75 to 200 mg per kg per day IM or IV, divided, every six to eight hours
One to three months, meningitis a concern	Ceftriaxone: Initial dose, 100 mg per kg IV; then 80 to 100 mg per kg per day IV, divided, every 12 to 24 hours; maximum dose, 4 g per 24 hours If S. pneumoniae is a concern, add vancomycin, 60 mg per kg per day IV, divided, every six hours
One to three months, urinary findings	Ceftriaxone, 75 mg per kg IV every 24 hours Alternative: Older than two months, oral cefixime (Suprax),‡ 8 mg per kg per day Alternative: Oral amoxicillin/clavulanate (Augmentin), 30 mg per kg per day (amoxicillin component), divided, every 12 hours
One to three months, suspected bacterial pneumonia, considering outpatient treatment	Oral amoxicillin, 90 mg per kg per day, divided, every 12 hours Alternative: Oral azithromycin (Zithromax), 10 mg per kg in single dose on day 1, then 5 mg per kg per day for days 2 to 5
Older than three months, high risk, no localizing signs	Ceftriaxone, 50 to 75 mg per kg IV once daily Alternative: Cefotaxime, 150 to 180 mg per kg per day IM or IV, divided, every six to eight hours
Older than three months, suspected bacterial pneumonia	Amoxicillin, 90 mg per kg per day orally, divided, every 12 hours; maximum, 500 mg per dose Alternative: Oral azithromycin, 10 mg per kg in single dose on day 1, then 5 mg per kg orally for days 2 to 5 Severe infection: Ceftriaxone, 50 to 200 mg per kg per day IM or IV, divided, every 12 to 24 hours; maximum, 2 g per day
Older than three months, urinary findings	Oral cefixime,‡ 8 mg per kg per day Alternative: Oral amoxicillin/clavulanate, 20 to 40 mg per kg per day (amoxicillin component), divided, every eight hours Alternative: Trimethoprim/sulfamethoxazole, 8 to 12 mg per kg per day (trimethoprim component) orally or IV, divided, every six to 12 hours