Pharmacokinetics and Pharmacodynamics of Antenatal Corticosteroids (PK-PD)

The PK-PD study is a sub-study of the ACTION-III trial, focusing on how antenatal corticosteroids affect pregnant women at risk of late preterm birth. Women are randomized into three groups to receive either dexamethasone phosphate (4×6 mg), betamethasone phosphate (4×2 mg), or placebo (IM).

Study Objectives:

• Pharmacokinetics (PK): To investigate how betamethasone phosphate (6 mg IM every 12 hours) is processed in the body using a population-based PK approach.
• Pharmacodynamics (PD): To evaluate the effects of betamethasone and dexamethasone (in the doses above) on pregnant women and their babies, compared to those who do not receive these corticosteroids.

By understanding these processes, we aim to optimize antenatal corticosteroid use for improving newborn outcomes in late preterm births. This research helps in developing safer and more effective treatment guidelines for mothers and infants.