Know your local resistance patterns and make sure to send a urine culture
Do not use nitrofurantoin in children (need bloodstream penetration)
Admit for IV antibiotics
Ceftazidime 150mg/kg/d divided every 6 h
Ceftazidime 150mg/kg/d divided every 6 h
Ceftriaxone 50mg/kg in ED
Cephalexin 50-100mg/kg/d in 4 divided doses x14d
Maximum dose (all ages) 4g/24hr
Maximum dose (all ages) 4g/24hr
Amoxicillin
Mild to moderate<unk> s (>40kg): 500mg PO BID for x10-14d
Cephalexin 50-100mg/kg/d in 4 divided doses x7d
Cefaclor 50-100 mg/kg/d divided in 3 doses x5d
Cefixime 8 mg/kg daily x 5d
Mild to moderate<unk> s (>40kg): 500mg PO BID for x10-14d
Consider 3 day course of treatment
Urinary tract infection 
Emergent
Pyelonephritis
Necrotizing Enterocolitis
Acute cystitis
Volvulus
Bladder trauma
Testicular torsion