title: Pharmacokinetics of 17-hydroxyprogesterone caproate in multifetal gestation.
abstract: OBJECTIVE
  The purpose of this study was to define the pharmacokinetic parameters of 17-hydroxyprogesterone caproate (17-OHPC) in multifetal gestation.
  
  
  METHODS
  Blood was obtained at 24-28 weeks' gestation and at 32-35 weeks gestation in 97 women with twin and 26 women with triplet gestation who were receiving 17-OHPC. Six of the women with twins had daily blood sampling for 7 days between 24 and 28 weeks' gestation, and pharmacokinetic parameters were estimated with the use of noncompartmental analysis. Modeling was applied to estimate the population parameters and to simulate various treatment scenarios.
  
  
  RESULTS
  The apparent half-life of 17-OHPC was 10 days. Body mass index significantly impacted 17-OHPC concentrations, but fetal number and parity did not. Apparent clearance was significantly greater in African American than in white women (P = .025).
  
  
  CONCLUSIONS
  This is the first pharmacokinetic analysis of 17-OHPC in pregnant women. Determination of half-life, covariates that affect plasma 17-OHPC concentrations, and the modeling of drug behavior provide insights into this drug's pharmacologic properties during multifetal pregnancy.
authors.affiliation: Department of Obstetrics, Gynecology, and Reproductive Sciences, School of Medicine, University of Pittsburgh, Pittsburgh, PA, USA.
authors.forename: Steve N
authors.initials: SN
authors.lastname: Caritis
authors.forename: Shringi
authors.initials: S
authors.lastname: Sharma
authors.forename: Raman
authors.initials: R
authors.lastname: Venkataramanan
authors.forename: Dwight J
authors.initials: DJ
authors.lastname: Rouse
authors.forename: Alan M
authors.initials: AM
authors.lastname: Peaceman
authors.forename: Anthony
authors.initials: A
authors.lastname: Sciscione
authors.forename: Catherine Y
authors.initials: CY
authors.lastname: Spong
authors.forename: Michael W
authors.initials: MW
authors.lastname: Varner
authors.forename: Fergal D
authors.initials: FD
authors.lastname: Malone
authors.forename: Jay D
authors.initials: JD
authors.lastname: Iams
authors.forename: Brian M
authors.initials: BM
authors.lastname: Mercer
authors.forename: John M
authors.initials: JM
authors.lastname: Thorp
authors.forename: Yoram
authors.initials: Y
authors.lastname: Sorokin
authors.forename: Marshall
authors.initials: M
authors.lastname: Carpenter
authors.forename: Julie
authors.initials: J
authors.lastname: Lo
authors.forename: Susan
authors.initials: S
authors.lastname: Ramin
authors.forename: Margaret
authors.initials: M
authors.lastname: Harper
mesh_terms: D000077713:17 alpha-Hydroxyprogesterone Caproate; D005260:Female; D006207:Half-Life; D006801:Humans; D006908:Hydroxyprogesterones / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics*; D011247:Pregnancy; D059286:Pregnancy, Triplet / Q000187:drug effects*; D059285:Pregnancy, Twin / Q000187:drug effects*; D047928:Premature Birth / Q000188:drug therapy*; D011372:Progestins / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics*; D016032:Randomized Controlled Trials as Topic
chemical_list: D006908:Hydroxyprogesterones; D011372:Progestins; D000077713:17 alpha-Hydroxyprogesterone Caproate