A Study of the Pharmacokinetics and Pharmacodynamics of Oxytocin at Elective Cesarean Delivery

( Anaesthesia . 2023;78(11):1347–1353. doi: 10.1111/anae.16109) Postpartum hemorrhage (PPH) is a leading cause of maternal mortality worldwide. The most common uterotonic agent used to prevent and treat PPH is oxytocin. In up to 38.8% of cases, oxytocin is unable to produce adequate uterine contractility and more uterotonic agents are required. Precise oxytocin dosing is ideal to balance PPH prevention/treatment and also avoid significant adverse side effects that can arise from high doses of oxytocin. While many factors contribute to the correct dosage for each individual, pharmacokinetic and pharmacodynamic data could assist in determining dosing for individual patients to both maximize desired effects and minimize adverse ones. This study was designed to obtain pharmacokinetic data to optimize the adjustment of oxytocin doses by patient weight, as well as to evaluate the relationship between serum oxytocin concentration and uterotonic and hemodynamic effects of the medication.