Nifedipine gastrointestinal therapeutic system (GITS) as an alternative to slow-release for tocolysis--tolerance and pharmacokinetic profile.
OBJECTIVE
To determine nifedipine plasma concentrations after a loading dose of nifedipine 10mg capsules, 40 mg over 1h followed by slow-release tablets (60 mg/d) versus gastrointestinal therapeutic system (GITS) tablets (90 mg/d) for tocolysis.


METHODS
Prospective study in 14 pregnant women treated for threatened preterm labor.


RESULTS
Following capsule administration there was a rapid rise in plasma concentration of drug achieving a peak of 97.5 microg/l (median) at 1h, then declined to 59.5 microg/l (median) at 5h. The concentration measured at 7200 min (120 h) was non-significantly higher in the slow-release group (median 25.5, range 6.9-67.2 microg/l) than in the GITS group (median 14.6, range 6.0-20.0 microg/l). Area under the curve (AUC) increased with the applied dose in both groups in a linear regression. Headache was more frequent in the slow-release group than in the GITS group (P=0.001).


CONCLUSIONS
GITS tablets 90 mg/d are an alternative dosage regimen to previous used slow-release tablets 60 mg/d for tocolysis with similar pharmacokinetic profile and a good tolerance. However, tocolysis with GITS tablets is simpler than that with slow-release tablets and may be associated with a higher compliance. GITS tablets are therefore also qualified for home monitoring.
Juon
Anna-Mengia
AM
Department of Obstetrics, Zurich University Hospital, Frauenklinikstrasse 10, CH-8091 Zurich, Switzerland.
Kühn-Velten
W Nikolaus
WN
Burkhardt
Tilo
T
Krähenmann
Franziska
F
Zimmermann
Roland
R
von Mandach
Ursula
U
D000284:Administration, Oral; D000328:Adult; D003692:Delayed-Action Preparations / Q000493:pharmacokinetics; D005260:Female; D006801:Humans; D009543:Nifedipine / Q000008:administration & dosage / Q000493:pharmacokinetics*; D007752:Obstetric Labor, Premature / Q000188:drug therapy*; D011247:Pregnancy; D015149:Tocolytic Agents / Q000008:administration & dosage / Q000493:pharmacokinetics*
D003692:Delayed-Action Preparations; D015149:Tocolytic Agents; D009543:Nifedipine