Neonatal dosing

Aciclovir IV

Gestational Age Starting dose (use actual body weight)
Neonates younger than 30 weeks post menstrual age 20 mg/kg/dose every 12 hours
Neonates 30 weeks post menstrual age or older 20 mg/kg/dose every 8 hours

Ampicillin IV (or Amoxycillin IV)

Gestational Age Post natal age Starting dose (use actual body weight)
Neonates ≤ 29 weeks post menstrual age Postnatal age 0 to 28 days 50 mg/kg/dose every 12 hours
Neonates ≤ 29 weeks post menstrual age Postnatal age more than 28 days 50 mg/kg/dose every 8 hours
Neonates 30 to 36 weeks post menstrual age Postnatal age 0 to 14 days 50 mg/kg/dose every 12 hours
Neonates 30 to 36 weeks post menstrual age Postnatal age 15 to 28 days 50 mg/kg/dose every 8 hours
Neonates 37 to 44 weeks post menstrual age Postnatal age 0 to 7 days 50 mg/kg/dose every 12 hours
Neonates 37 to 44 weeks post menstrual age Postnatal age 8 to 28 days 50 mg/kg/dose every 8 hours
Neonates ≥ 45 weeks post menstrual age All 50 mg/kg/dose every 6 hours

Benzylpenicillin IV

Gestational Age Post natal age Starting dose (use actual body weight)
Neonates ≤ 29 weeks post menstrual age Postnatal age 0 to 28 days 60 mg/kg/dose every 12 hours
Neonates ≤ 29 weeks post menstrual age Postnatal age more than 28 days 60 mg/kg/dose every 8 hours
Neonates 30 to 36 weeks post menstrual age Postnatal age 0 to 14 days 60 mg/kg/dose every 12 hours
Neonates 30 to 36 weeks post menstrual age Postnatal age 15 to 28 days 60 mg/kg/dose every 8 hours
Neonates 37 to 44 weeks post menstrual age Postnatal age 0 to 7 days 60 mg/kg/dose every 12 hours
Neonates 37 to 44 weeks post menstrual age Postnatal age 8 to 28 days 60 mg/kg/dose every 8 hours
Neonates ≥ 45 weeks post menstrual age ALL 60 mg/kg/dose every 6 hours

Cefotaxime IV

Gestational Age Post natal age Starting dose (use actual body weight)
Neonates less than 32 weeks post menstrual age Postnatal age 0 to 7 days 50 mg/kg/dose every 12 hours
Neonates less than 32 weeks post menstrual age Postnatal age 8 to 28 days 50 mg/kg/dose every 8 hours
Neonates more than 32 weeks post menstrual age Postnatal age 0 to 7 days 50 mg/kg/dose every 12 hours
Neonates more than 32 weeks post menstrual age Postnatal age 8 to 28 days 50 mg/kg/dose every 6 hours

Clindamycin IV

Gestational Age Post natal age Starting dose (use actual body weight)
Neonates ≤ 29 weeks post menstrual age Postnatal age 0 to 28 days 5 mg/kg/dose every 12 hours
Neonates ≤ 29 weeks post menstrual age Postnatal age more than 28 days 5 mg/kg/dose every 8 hours
Neonates 30 to 36 weeks post menstrual age Postnatal age 0 to 14 days 5 mg/kg/dose every 12 hours
Neonates 30 to 36 weeks post menstrual age Postnatal age 15 to 28 days 5 mg/kg/dose every 8 hours
Neonates 37 to 44 weeks post menstrual age Postnatal age 0 to 7 days 5 mg/kg/dose every 12 hours
Neonates 37 to 44 weeks post menstrual age Postnatal age 8 to 28 days 5 mg/kg/dose every 8 hours
Neonates ≥ 45 weeks post menstrual age All 5 mg/kg/dose every 6 hours

Flucloxacillin IV

Gestational Age Post natal age Starting dose (use actual body weight)
Term/ premature neonates Postnatal age 0 to 7 days 50 mg/kg/dose every 12 hours
Term/ premature neonates Postnatal age 8 to 28 days 50 mg/kg/dose every 8 hours

Gentamicin IV**

Perform therapeutic drug monitoring (TDM)** (Dose based on ideal body weight)

Gestational Age Post natal age Starting dose (use ideal body weight)
Neonates younger ≤ 29 weeks post menstrual age Postnatal age 0 to 14 days 5 mg/kg/dose every 48 hours**
Neonates younger ≤ 29 weeks post menstrual age Postnatal age 15 to 28 days 5 mg/kg/dose every 36 hours**
Neonates 30 to 34 weeks post menstrual age Postnatal age 0 to 28 days 5 mg/kg/dose every 36 hours**
Neonates 35 weeks post menstrual age or older Postnatal age 0 to 28 days 5 mg/kg/dose every 24 hours**

Meropenem IV (severe/CNS infection)

Gestational Age Post natal age Starting dose (use actual body weight)
Neonates – ALL gestational ages Postnatal age 0 to 7 days 40 mg/kg/dose every 12 hours
Neonates – ALL gestational ages Postnatal age 8 to 28 days 40 mg/kg/dose every 8 hours

Metronidazole IV

Gestational Age Post natal age Starting dose (use actual body weight)
Neonates ≤ 29 weeks post menstrual age Postnatal age 0 to 28 days 15 mg/kg IV as a single loading dose, then 7.5 mg/kg/dose every 24 hours
Neonates ≤ 29 weeks post menstrual age Postnatal age more than 28 days 15 mg/kg IV as a single loading dose, then 7.5 mg/kg/dose every 12 hours
Neonates 30 to 36 weeks post menstrual age Postnatal age 0 to 14 days 15 mg/kg IV as a single loading dose, then 7.5 mg/kg/dose every 12 hours
Neonates 30 to 36 weeks post menstrual age Postnatal age 15 to 28 days 15 mg/kg IV as a single loading dose, then 7.5 mg/kg/dose every 8 hours
Neonates 37 to 44 weeks post menstrual age Postnatal age 0 to 7 days 15 mg/kg IV as a single loading dose, then 7.5 mg/kg/dose every 12 hours
Neonates 37 to 44 weeks post menstrual age Postnatal age 8 to 28 days 15mg/kg IV as a single loading dose, then 7.5 mg/kg/dose every 8 hours
Neonates ≥ 45 weeks post menstrual age All 15 mg/kg IV as a single loading dose, then 7.5 mg/kg/dose every 8 hours

Vancomycin IV**

Perform therapeutic drug monitoring (TDM)**

Gestational Age Post natal age Starting dose (use actual body weight)
Neonates ≤ 29 weeks post menstrual age Postnatal age 0 to 14 days 15 mg/kg/dose IV 18 hourly**
Neonates ≤ 29 weeks post menstrual age Postnatal age 15 to 28 days 15 mg/kg/dose IV 12 hourly**
Neonates 30 to 36 weeks post menstrual age Postnatal age 0 to 14 days 15 mg/kg/dose IV 12 hourly**
Neonates 30 to 36 weeks post menstrual age Postnatal age 15 to 28 days 15 mg/kg/dose IV 8 hourly**
Neonates 37 to 44 weeks post menstrual age Postnatal age 0 to 7 days 15 mg/kg/dose IV 12 hourly**
Neonates 37 to 44 weeks post menstrual age Postnatal age 8 to 28 days 15 mg/kg/dose IV 8 hourly**
Neonates ≥ 45 weeks post menstrual age All 15 mg/kg/dose IV 6 hourly**

Definitions

Postmenstrual age:
The time elapsed between the first day of the last menstrual period and birth (gestational age) plus the time elapsed after birth (postnatal age).

Renal function and drug elimination are most strongly correlated with Postmenstrual Age.

Perform therapeutic drug monitoring (TDM) for Gentamicin and Vancomycin.