Weight-based doses for neonates (0–28 days). Amoxicillin, gentamicin, phenobarbitone, caffeine citrate, ampicillin, vitamin K, fluconazole & more.
BNF for Children 2024 · WHO guidelines. Offline-capable.
For qualified healthcare professionals only.
Neonatal dosing is the highest-stakes clinical task — errors can be fatal. All doses sourced from BNF for Children 2024, WHO Essential Medicines for Children, and national neonatal protocols for Nigeria (FMOH), Kenya (MOH), and Ghana (GHS).
Always apply clinical judgement. Confirm gestational age and postnatal age before dosing.
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Clinically reviewed by
Dr. Chioma Okafor, FWACP (Paeds)
Consultant Paediatrician, University of Nigeria Teaching Hospital
Neonatal drug dosing errors are among the highest-risk medication errors in clinical practice. The unique pharmacokinetics of newborns — especially preterm neonates — require weight-based, age-adjusted dosing that differs fundamentally from older children and adults. Neonates have immature hepatic cytochrome P450 enzyme systems, reduced renal glomerular filtration, altered volume of distribution, and variable protein binding. These factors result in prolonged drug half-lives, increased toxicity risk, and unpredictable drug levels with standard paediatric doses. This calculator is designed for qualified neonatal clinicians in low-resource African settings, based on WHO Essential Medicines for Neonatal Care, the British National Formulary for Children (BNFc), and validated regional neonatal formularies.
Gentamicin uses extended-interval dosing in neonates: term neonates ≥37 weeks: 4–5 mg/kg IV every 24 hours. Preterm 32–36 weeks: 4 mg/kg every 36 hours. <32 weeks: 4 mg/kg every 48 hours. If treating for >48 hours, monitor trough levels (<1 mg/L) to avoid ototoxicity and nephrotoxicity.
Phenobarbitone is first-line: loading dose 20 mg/kg IV slowly over 15–20 minutes (maximum rate 1 mg/kg/min). If seizures continue, give a further 10 mg/kg after 15–30 minutes. Maintenance: 3–5 mg/kg/day in 1–2 divided doses from 12–24 hours post-loading. Monitor for respiratory depression.
Never. Neonatal doses are entirely separate from paediatric doses and must not be extrapolated. Even within the neonatal period, dosing changes significantly by gestational age and postnatal day. Always use a validated neonatal formulary. Using standard paediatric doses in neonates risks serious toxicity and death.
Neonates have fundamentally different pharmacokinetics from older children and adults. Renal tubular function and glomerular filtration are immature, leading to prolonged drug half-lives. Hepatic enzyme systems (particularly CYP450 pathways) are incompletely developed. Body water distribution differs significantly. Protein binding is reduced. These factors mean standard mg/kg doses used in older children can cause toxicity in neonates. Gestational age, postnatal age, and weight must all be considered simultaneously — this is why specialist neonatal formularies (BNFc, Neofax) are essential.
Kernicterus is irreversible brain damage caused by deposition of unconjugated bilirubin in basal ganglia. Several drugs displace bilirubin from albumin binding sites, increasing free bilirubin and kernicterus risk. Drugs to avoid in jaundiced neonates or premature infants include: ceftriaxone (displaces bilirubin from albumin — never give with calcium infusions), sulphonamides (including co-trimoxazole), vitamin K analogues (menadione), and high-dose aspirin. Always cross-reference neonatal drug choices against a validated neonatal formulary.
📋 Guideline basis: BNFc 2024 · Neofax · WHO Pocket Book 2013 · Last reviewed: January 2025 · Next review due: January 2026 · Disclaimer · Report an error
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