Aminoglycoside — Neonatal Sepsis / Gram-Negative Infections in Children Pregnancy: Avoid unless essential — cochlear toxicity in fetus; use with caution for life-threatening maternal infection

Gentamicin (Paediatric)

Brand names: Cidomycin, Genticin

Adult dose

Dose: 5–7 mg/kg IV once daily (extended-interval dosing)

Route: IV infusion over 30–60 minutes

Frequency: Once daily

Max: Guided by TDM — trough <1 mg/L

Adult reference — see paediatric dose section

Paediatric dose

Dose: Neonates <29 weeks: 5 mg/kg every 48 hours; 29–35 weeks: 4.5 mg/kg every 36 hours; ≥35 weeks/term neonates: 4.5 mg/kg every 36 hours (first week), then every 24 hours; Children 1 month–18 years: 7 mg/kg once daily mg/kg

Route: IV infusion over 30–60 minutes

Frequency: Age and gestational-age dependent (see notes)

Max: 7 mg/kg per dose

BNFc: TDM MANDATORY in neonates and children — trough pre-dose: target <1 mg/L (extended-interval); check trough before 3rd or 4th dose. NICU protocols: hartmann neonatal gentamicin dosing calculator used in many UK NICUs. In neonatal sepsis: combined with ampicillin (covers Group B Strep and Listeria). Gentamicin infusion must be given over at least 30 minutes — bolus injection risks neuromuscular blockade.

Dose adjustments

Renal

Extend dosing interval based on trough levels and GFR; TDM essential in renal impairment

Hepatic

No adjustment required

Paediatric weight-based calculator

Patient weight (kg)

Clinical pearls

Neonatal extended-interval dosing (EID): based on developmental pharmacokinetics — premature neonates have immature GFR and larger volume of distribution; half-life 10–18 hours in premature vs 2 hours in adults; dose intervals adjusted to gestational and postnatal age
Trough monitoring essential: check pre-dose trough before 3rd/4th dose — target <1 mg/L for once-daily dosing; if trough elevated, extend interval rather than reduce dose (concentration-dependent killing requires adequate peak)
Ototoxicity: cochlear toxicity affects high-frequency hearing first — often not detected without formal audiometry; all neonates receiving gentamicin should have neonatal hearing screen; cumulative exposure increases risk
Synergy with ampicillin: aminoglycosides disrupt cell wall uptake (aminoglycosides need intact cell wall — beta-lactam creates pores allowing aminoglycoside entry) — classical synergy for Enterococcal endocarditis and neonatal GBS sepsis

Contraindications

Pre-existing hearing loss or vestibular disorder
Myasthenia gravis
Concurrent nephrotoxic or ototoxic agents without close TDM

Side effects

Nephrotoxicity (reversible acute tubular necrosis)
Ototoxicity (cochlear — irreversible; vestibular)
Neuromuscular blockade (rapid administration)
Rash

Interactions

Vancomycin — additive nephrotoxicity
Loop diuretics — additive ototoxicity
Amphotericin — additive nephrotoxicity
Neuromuscular blocking agents — enhanced blockade

Monitoring

Trough serum level (target <1 mg/L — check before 3rd dose)
Renal function (U&E, creatinine — daily in neonates)
Hearing assessment (neonatal screening post-course)
Urine output

Reference: BNF for Children; BPNG Neonatal Formulary; PHE Neonatal Sepsis Guidelines; NICE NG195 (Neonatal Infection). Verify against your local formulary and the latest BNF before prescribing.

Curated clinical cross-links plus same-class fallbacks.

Calculators

Pathways