Pediatric dosing of antimicrobials

From IDWiki

Antibiotics

Penicillins

Drug Indication Age and weight 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

Cephalosporins

Drug Indication Age and weight Dose
First generation
Cefazolin IV/IM usual dose 75-150 mg/kg/day split q8h (max 2 g/dose and 6 g/day)
Cephalexin PO usual dose 25-100 mg/kg/day split qid
osteomyelitis (oral step-down) 100-150 mg/kg/day split qid
Second generation
Cefuroxime IV/IM usual dose 100-150 mg/kg/day split q8h (max 2 g/dose)
Cefuroxime azetil PO poor bioavailability; not recommended
Cefprozil PO usual dose 15-30 mg/kg/day split bid (max 1 g/day)
Third generation
Cefotaxime IV/IM usual dose 0-7 days 50 mg/kg/dose q8h
>7 days 50 mg/kg/dose q8h
infants and children 100-200 mg/kg/day split q6-8h (max 6 g/day)
meningitis 0-7 days 50 mg/kg/dose q8h
>7 days 50 mg/kg/dose q6h
infants and children 200-300 mg/kg/day split q6h (max 4 g/dose and 12 g/day)
Ceftriaxone IM/IV usual dose >1 month 50-75 mg/kg q24h (max 2 g/day)
meningitis >1 month 100 mg/kg/day split q12-24h (max 2 g/dose and 4 g/day)
gonorrhea ≥9 years 250 mg IM once
<9 years 50 mg/kg IM once (max 250 mg)
Ceftazidime IM/IV usual dose 75-150 mg/kg/day split q8h (max 2 g/dose and 6 g/day)
meningitis or cystic fibrosis 200 mg/kg/day split q6-8h (max 6 g/day)
Cefixime PO usual dose 8 mg/kg/day split q12-24h (max 400 mg/day)

Carbapenems

Drug Indication Age and weight Dose
Meropenem usual dose 20 mg/kg/dose q8h (max 1 g/dose)
meningitis 40 mg/kg/dose q8h (max 2 g/dose)
Ertapenem usual dose 3 months to 12 years 15 mg/kg/dose q12h (max 500 mg/dose)
≥13 years 1 g daily

Glycopeptides

Drug Indication Age and weight Dose
Vancomycin IV usual dose 40-60 mg/kg/day split q6-12h (max 2+ g/day)
meningitis or MRSA 60 mg/kg/day split q6-8h (max 4 g/day)
Vancomycin PO Clostridium difficile 10 mg/kg/dose q6h (max 125 mg/dose)

Macrolides

Drug Indication Age and weight Dose
Clarithromycin PO usual dose 7.5 mg/kg/dose bid
Azithromycin PO/IV usual dose 10 mg/kg (max 500 mg) once, then 5 mg/kg (max 250 mg) daily for 4 days
pertussis <6 months 10 mg/kg q24h for 5 days
≥6 months 10 mg/kg once (max 500 mg) then 5 mg/kg dailys (max 250 mg)
chlamydia <9 years 20 mg/kg (max 1 g) once
≥9 years 1 g once
chlamydial conjunctivitis infants 20 mg/kg once daily for 3 days

Aminoglycosides

Drug Indication Age and weight Dose
Tobramycin IV usual dose 5-7 mg/kg/dose q24h
cystic fibrosis 10-12 mg/kg/dose q24h
Tobramycin INH cystic fibrosis 80 mg bid to tid
Gentamicin IV usual dose ≤7 days 4 mg/kg/dose q24h
>7 days 5 mg/kg/dose q24h
infants and children 5-7 mg/kg/dose q24h
synergy for Gram-positive infections 1 mg/kg/dose q8h
  • Extended-frequency dosing of aminoglycosides is preferred for all patients older than 1 month with the exception of endocarditis or extensive burns
  • Monitor trough levels pre-second dose, with target of <1 mg/L

Fluoroquinolones

Drug Indication Age and weight Dose
Ciprofloxacin IV/PO usual dose 20-30 mg/kg/day split q12h (max 400 mg/dose IV or 750 mg/dose PO)
Levofloxacin PO/IV usual dose ≤5 years 10 mg/kg q12h
>5 years 10 mg/kg daily (max 750 mg/day)

Miscellaneous

Drug Indication Age and weight Dose
Lincosamides
Clindamycin IV usual dose 20-40 mg/kg/day split q6h (max 600 mg/dose)
toxic shock syndrome or necrotizing fasciitis 600-900 mg q8h
Clindamycin PO usual dose 10-30 mg/kg/day split q6-8h
Nitroimidazole
Metronidazole PO/IV anaerobic infections 20-30 mg/kg/day split q8-12h (max 1500 mg/day IV or 2000 mg/day PO)
severe infections 50 mg/kg/day split q8h
C. difficile infection 30 mg/kg/day split q6-8h (max 1500 mg/day)
Sulfonamides
Co-trimoxazole PO/IV usual dose 8-10 mg/kg/day TMP split q12h
MRSA 8-12 mg/kg/day TMP split q12h
Pneumocystis pneumonia (treatment) 15-20 mg/kg/day TMP split q6-8h
Pneumocystis pneumonia (prophylaxis) 3-5 mg/kg/day TMP split q12h on Mon-Wed-Fri
Trimethoprim PO UTI (prophylaxis) 2-3 mg/kg/day split q12h
Others
Nitrofurantoin PO UTI (treatment) 5-7 mg/kg/day split q6h (max 400 mg/day)
UTI (prophylaxis) 1-2 mg/kg/day daily
Macrobid PO UTI (treatment) >12 years 100 mg bid

Antifungals

Drug Indication Age and weight Dose
Liposomal amphotericin B IV usual dose 3-5 mg/kg daily
severe infections 10 mg/kg daily
Caspofungin IV usual dose 70 mg/m2 once (max 70 mg) followed by 50 mg/m2 daily (max 50 mg)
Nystatin PO oral candidiasis infants 100,000 U swish & swallow qid
children 250,000 U swish & swallow qid
adolescents 500,000 U swish & swallow qid

Antivirals

Drug Indication Age Weight Dose
Acyclovir IV HSV and VZV 1-3 month infants 20 mg/kg/dose q8h
HSV encephalitis 3 months to 12 years 10-15 mg/kg/dose q8h
>12 years 10 mg/kg/dose q8h
HSV (severe or immunocompromised) 5-10 mg/kg/dose q8h
VZV (severe or immunocompromised) 10 mg/kg/dose q8h
Acyclovir PO HSV (mild-moderate and immunocompetent) 30-50 mg/kg/day split 3-5 times daily
HSV (severe or immunocompromised, step-down) 60-80 mg/kg/day split 3-5 times daily
VZV (immunocompetent) 80 mg/kg/day split 3-5 times daily
VZV (severe or immunocompromised, step-down) 80 mg/kg/day split 3-5 times daily
Valacyclovir PO HSV cold sores 3 months to 11 years 6 to <15 kg 250 mg bid x3 days
3 months to 11 years 15 to <30 kg 500 mg bid x3 days
3 months to 11 years 30 to 36 kg 750 mg bid x3 days
3 months to 11 years >36 kg 1 g bid x3 days
≥12 years 2 g bid x1 day
VZV ≥2 years any 20 mg/kg tid
6 to <15 kg 250 mg tid x5 days
15 to <30 kg 500 mg tid x5 days
30 to 36 kg 750 mg tid x5 days
>36 kg 1 g tid x5 days
Oseltamivir PO influenza 1 to 8 months (term) 3-3.5 kg 9 mg bid
3.6-4.5 kg 12 mg bid
4.6-5.5 kg 15 mg bid
5.6-6.5 kg 18 mg bid
6.6-7.5 kg 21 mg bid
7.6-8.5 kg 24 mg
8.6-9.5 kg 27 mg bid
≥9.6 kg 30 mg bid
9 to 11 months 3-3.5 kg 12 mg bid
3.6-4.5 kg 15 mg bid
4.6-5.5 kg 18 mg bid
5.6-6.5 kg 21 mg bid
6.6-7.5 kg 24 mg bid
7.6-8.5 kg 27 mg bid
≥8.6 kg 30 mg bid
>12 months <15 kg 30 mg bid
15-23 kg 45 mg bid
23-40 kg 60 mg bid
>40 kg 75 mg bid

Antimalarials

Drug Indication Age and weight Dose
Artesunate malaria (treatment) <20 kg 3 mg/kg/dose at 0, 12, 24, and 48 hours
>20 kg 2.4 mg/kg/dose at 0, 12, 24, and 48 hours
Atovaquone-proguanil PO malaria (treatment) 5-8 kg 125 mg-50 mg (2 peds tabs) daily x3 days
8.01-10 kg 187.5 mg-75 mg (3 peds tabs) daily x3 days
10.01-20 kg 250 mg-100 mg (1 adult tab) daily x3 days
20.01-30 kg 500 mg-200 mg (2 adult tabs) daily x3 days
30.01-40 kg 750 mg-300 mg (3 adult tabs) daily x3 days
>40 kg 1000 mg-400 mg (4 adult tabs) daily x3 days
malaria (prophylaxis) 5-8 kg 31.25 mg-12.5 mg (1/2 peds tabs) daily
8.01-10 kg 46.875 mg-18.75 mg (3/4 peds tabs) daily
10.01-20 kg 62.5 mg-25 mg (1 peds tab) daily
20.01-30 kg 125 mg-50 mg (2 peds tabs) daily
30.01-40 kg 187.5 mg-75 mg(3 peds tabs) daily
>40 kg 250 mg-100 mg (1 adult tab) daily