How does gestational age affect drug dosing in neonates?

Preterm neonates have immature renal and hepatic function, higher total body water (Vd), lower albumin binding, and immature CYP450 enzymes. GA and postnatal age together determine pharmacokinetic maturation for dose frequency and amount.

What is postmenstrual age (PMA) and how is it used in neonatal dosing?

PMA = gestational age + postnatal age in weeks. Most neonatal dosing guidelines (e.g., BNF for Children, Neofax) use PMA to determine dosing frequency as GFR and elimination mature predictably with increasing PMA.

Neonatal Gestational Age Weight-Based Dosing

Calculate weight-based drug doses in neonates accounting for gestational age (GA) and postnatal age (PNA) effects on pharmacokinetic maturation, including GFR, hepatic enzyme activity, and volume of distribution.

Use the full interactive calculator below, or

Neonatal Gestational Age Weight-Based Dosing

Frequently Asked Questions

How does gestational age affect drug dosing in neonates?

What is postmenstrual age (PMA) and how is it used in neonatal dosing?