Early-onset (≤72 h) (Group B Streptococcus · Escherichia coli and other enteric Gram-negatives · Listeria monocytogenes (AAP Red Book, WHO newborn infection guidance, SSC pediatric 2020))
Late-onset (>72 h) (Coagulase-negative staphylococci · S. aureus (including MRSA) · Gram-negative bacilli · Candida in NICU — broaden per healthcare exposure and local epidemiology (AAP, ESPNIC))
First-line therapy
Ampicillin • i.v. • 50–50 mg/kg/dose • 3×/day
Max 2000 mg/dose · Max 8000 mg/day · Duration: 10–14 days · Neonatal sepsis — interval q8h–q12h by GA/PNA; PNA >28 days may use q6h; mandatory Listeria/GBS coverage (Nelson's, Red Book)
• Ampicillin neonatal intervals (non-meningitis sepsis): q8h–q12h by GA/PNA — ≤34 weeks PNA 0–7 days 50 mg/kg q12h; >34 weeks PNA 0–28 days 50 mg/kg q8h; PNA >28 days 50 mg/kg q6h (Nelson's, Red Book). Calculator uses 50 mg/kg q8h as term-neonate fallback — verify with NICU protocol.
• Gentamicin GA/PNA extended-interval dosing (Red Book/Nelson): GA <30 weeks PNA ≤14 days 5 mg/kg q48h; GA 30–34 weeks PNA ≤10 days 5 mg/kg q36h; GA ≥35 weeks PNA ≤7 days 4 mg/kg q24h; GA ≥35 weeks PNA 8–60 days 5 mg/kg q24h. Calculator fallback 5 mg/kg once daily — verify interval and TDM with pharmacy.
• Obtain blood culture (and site-specific cultures) before first antibiotic dose when feasible — do not delay empiric therapy >30–60 min in unstable neonates (SSC pediatric 2020, AAP).
• Time to first antibiotic: administer empiric IV antibiotics within **1 hour** of sepsis recognition (SSC pediatric 2020 strong recommendation).
• Add vancomycin when MRSA risk: purulent infection, prior MRSA, healthcare-associated late-onset sepsis, or hemodynamic instability with high local MRSA prevalence — 10 mg/kg q12h in neonates (Red Book, IDSA SSTI).
Enter weight on Kids to calculate doses
Gentamicin • i.v./i.m. • 5–5 mg/kg/dose • 1×/day
Max 80 mg/dose · Duration: 10–14 days · Extended-interval aminoglycoside — dose and interval vary by GA/PNA (see high-dose indications); monitor levels if therapy >48–72 h
Enter weight on Kids to calculate doses
Cefotaxime • i.v. • 50–50 mg/kg/dose • 3×/day
Max 2000 mg/dose · Max 15000 mg/day · Duration: 10–14 days · Neonatal sepsis — 50 mg/kg q8h (150 mg/kg/day); may increase to q6h in older neonates per NICU protocol; pair with ampicillin for Listeria (AAP Red Book, WHO)
• Cefotaxime ± ampicillin: per local NICU protocol when ampicillin/gentamicin unsuitable (renal concern for aminoglycoside, gentamicin resistance concern) — always maintain ampicillin for Listeria in neonates (AAP Red Book, WHO).
• Ceftriaxone generally avoided in neonates with hyperbilirubinemia/jaundice — prefer cefotaxime (AAP Red Book, Nelson's).
• Vancomycin add-on: late-onset healthcare-associated sepsis, purulent skin/line infection, prior MRSA, or clinical failure on beta-lactam at 48 h (AAP Red Book, IDSA).
• Clindamycin: suspected CA-MRSA with toxin-mediated disease (necrotizing SSTI) when isolate clindamycin-susceptible — not preferred monotherapy for neonatal sepsis; pair with Gram-negative coverage (IDSA SSTI, CDC GAS guidance).
• Meropenem (20 mg/kg q8h): severe sepsis with suspected ESBL Gram-negatives or beta-lactam allergy — specialist-guided; pair with ampicillin if Listeria risk (ESPID, IDSA principles).
Enter weight on Kids to calculate doses
Ampicillin • i.v. • 50–50 mg/kg/dose • 3×/day
Max 2000 mg/dose · Duration: 10–14 days · Mandatory add-on for Listeria/enterococcal coverage — do not use cefotaxime monotherapy in neonates (AAP Red Book)
• Septic shock: sepsis with cardiovascular dysfunction — hypotension for age, need for vasoactive drugs, or clinical signs of poor perfusion despite ≥40 mL/kg fluid resuscitation (SSC pediatric 2020 definitions).
• Blood cultures before antibiotics when feasible without clinically meaningful delay — obtain at least 1 mL blood per culture bottle; add CSF, urine, wound, or line cultures per suspected source; do not withhold antibiotics in unstable patients (SSC, AAP).
• Time to first antibiotic within **1 hour** of sepsis recognition; fluid resuscitation with crystalloid **10–20 mL/kg** boluses, reassess after each — up to 40–60 mL/kg in first hour if needed without hepatomegaly/rales (SSC pediatric 2020, WHO Pocket Book).
• NICU/PICU admission for all neonates with suspected sepsis or shock; urgent source control (line removal, surgical drainage); reassess empiric regimen at 48–72 h with culture results; monitor lactate, perfusion, urine output, glucose, and electrolytes (SSC, ESPNIC, AAP).
• Surviving Sepsis Campaign — International guidelines for management of septic shock and sepsis-associated organ dysfunction in children (2020)
• AAP Red Book — Neonatal sepsis and serious bacterial infection in young infants (2024)
• WHO Pocket Book of Hospital Care for Children — Severe bacterial infection and newborn danger signs (2022)
