Pharmacology and placental transport of 17-hydroxyprogesterone caproate in singleton gestation

• Published in: American journal of obstetrics and gynecology Vol. 207; no. 5; pp. 398.e1 - 398.e8
• Main Authors: Caritis, Steve N., Sharma, Shringi, Venkataramanan, Raman, Hankins, Gary D., Miodovnik, Menachem, Hebert, Mary F., Umans, Jason G., Benedetti, Thomas, Mattison, Donald, Zajicek, Anne, Fischer, Dawn, Jackson, Aimee
• Format: Journal Article
• Language: English
• Published: New York, NY Mosby, Inc 01.11.2012; Elsevier
• Subjects: 17 alpha-Hydroxyprogesterone Caproate; Adult; Biological and medical sciences; Biological Transport - physiology; Body Mass Index; cord blood; Female; Fetal Blood - chemistry; Gynecology. Andrology. Obstetrics; Humans; Hydroxyprogesterones - blood; Hydroxyprogesterones - pharmacokinetics; Hydroxyprogesterones - pharmacology; Medical sciences; Obstetrics and Gynecology; pharmacokinetics; placenta; Placenta - metabolism; Pregnancy; preterm birth; Progestins - blood; Progestins - pharmacokinetics; Progestins - pharmacology; Young Adult; preterm birth; pharmacokinetics; placenta; cord blood; Pregnancy; Placenta; Hydroxyprogesterone caproate; Gynecology; Pharmacology; Transport; Obstetrics
• ISSN: 0002-9378; 1097-6868; 1097-6868
• DOI: 10.1016/j.ajog.2012.08.015

The purpose of this study was to estimate pharmacokinetic parameters and to evaluate placental transport of 17-hydroxyprogesterone caproate (17-OHPC) in singleton gestation. Sixty-one women who received weekly injections of 17-OHPC underwent 2 pharmacokinetic studies at 20 + 0 to 24 + 6 weeks' gestation (study 1) and 31 + 0 to 34 + 6 weeks' gestation (study 2); daily blood samples were obtained between injections. In 18 women, blood samples were obtained over a 28-day period beyond the last injection (extended study). Maternal and/or cord blood were obtained at delivery. The half-life (median ± SD) of 17-OHPC was 16.2 ± 6 days. Concentrations of 17-OHPC were higher during study 2 than during study 1. Body mass index affected maternal 17-OHPC concentrations. Cord:maternal 17-OHPC concentration ratios averaged 0.2; 17-OHPC was detectible in cord plasma 44 days after the last maternal injection. The apparent half-life of 17-OHPC is long, and pharmacokinetic parameters vary widely between subjects and are affected by maternal body mass index. The drug crosses the placental barrier.