Pediatric dosing of antimicrobials

Antibiotics

Penicillins

Drug	Indication	Age	Weight	Usual dose
Penicillin G IV/IM	moderate to severe infections			100,000 to 400,000 U/kg/day split q4-6h (max 24 MU/day)
	meningitis			400,000 U/kg/day split q4h (max 24 MU/day)
Penicillin VK PO	mild to moderate infections			25-50 mg/kg/day split q8-12h
	rheumatic fever (treatment)		≤ 27 kg	300 mg PO bid x10 days
			> 27 kg	600 mg PO bid x 10 days
	rheumatic fever (prophylaxis)	> 5 years		300 mg PO bid
	asplenia (prophylaxis)	6 months to 5 years		150 mg PO bid
		> 5 years		300 mg PO bid
Cloxacillin IV	methicillin-susceptible Staphylococcus aureus			100-200 mg/kg/day split q4-6h (max 2g/dose and 12 g/day)
Cloxacillin PO				use cephalexin instead
Ampicillin IV	usual dose	neonates		100-200 mg/kg/day split q6-8h
		infants and children		100-200 mg/kg/day split q6h (max 2 g/dose)
	meningitis	neonates		300 mg/kg/day split q6-8h
		infants and children		300-400 mg/kg/day split q4-6h (max 2 g/dose)
Amoxicillin PO	usual dose			40-50 mg/kg/day split q8h
	Streptococcus pneumoniae			80-90 mg/kg/day split q8h
	Group A Streptococcus pharyngitis			50 mg/kg once daily x10 days (max 1 g/dose)
Amoxicillin-clavulanic acid PO	usual dose			30-50 mg/kg/day (amox component) split q8-12h (max 875 mg/dose)
	Streptococcus pneumoniae			80-90 mg/kg/day (amox component) split q8-12h (max 875 mg/dose)
Piperacillin-tazobactam IV	usual dose			240-300 mg/kg/day (pip component) split q6-8h
	Pseudomonas aeruginosa or cystic fibrosis			400 mg/kg/day split q6h