title: Nifedipine serum levels in pregnant women undergoing tocolysis with nifedipine.
abstract: The objective of our cross-sectional, observational study was to investigate nifedipine serum levels in pregnant women undergoing tocolysis. A total of 24 pregnant women, 22-34 weeks' gestation, who were administered nifedipine for treatment of pre-term labour, were enrolled in the study. Blood samples were taken 12 h after the oral application of 60 mg nifedipine in 'continuous release' form (Adalat CR 60). Nifedipine serum levels were measured with liquid chromatography. Nifedipine serum levels spread between 6 and 101 ng/ml (17-292 nmol/l). There was no correlation between nifedipine levels and body mass index (BMI), or between nifedipine levels and gestational age. During nifedipine tocolysis, 11 of 24 patients (45.8%) had mild side-effects, mostly headache. The side-effects were not dose-related. Despite the standardised dosage and standardised blood sampling nifedipine serum levels spread in a wide range. There is no need to adjust the dose of nifedipine to BMI or to gestational age.
authors.affiliation: Department of Frauenheilkunde, Klinik für Geburtshilfe, Universitäts Spital, Zürich, Switzerland. tina.zodan@usz.ch
authors.forename: T Zodan
authors.initials: TZ
authors.lastname: Marin
authors.forename: R
authors.initials: R
authors.lastname: Meier
authors.forename: F
authors.initials: F
authors.lastname: Kraehenmann
authors.forename: T
authors.initials: T
authors.lastname: Burkhardt
authors.forename: R
authors.initials: R
authors.lastname: Zimmermann
mesh_terms: D000284:Administration, Oral; D002626:Chemistry, Pharmaceutical; D003430:Cross-Sectional Studies; D005260:Female; D005865:Gestational Age; D006801:Humans; D009543:Nifedipine / Q000008:administration & dosage / Q000009:adverse effects / Q000097:blood / Q000493:pharmacokinetics* / Q000627:therapeutic use; D007752:Obstetric Labor, Premature / Q000097:blood / Q000517:prevention & control*; D011247:Pregnancy; D011262:Pregnancy Trimester, Second; D011263:Pregnancy Trimester, Third; D015149:Tocolytic Agents / Q000008:administration & dosage / Q000009:adverse effects / Q000097:blood / Q000493:pharmacokinetics* / Q000627:therapeutic use
chemical_list: D015149:Tocolytic Agents; D009543:Nifedipine