von Mandach U, Böni R, Danko J, Huch R, Huch A
Department of Obstetrics and Gynecology, University of Zurich, Switzerland.
Arzneimittelforschung. 1995 Feb;45(2):186-9.
The beta 2-sympathomimetic drug fenoterol (fenoterol hydrobromide, CAS 1944-12-3, Partusisten) is routinely used to inhibit uterine contractions (tocolysis). Investigations of plasma concentrations of those receiving i.v. or oral tocolysis often show different results, both within particular groups of pregnant women and in comparison with non-pregnant persons. The aim of this study was to determine the pharmacokinetics of fenoterol in pregnant women, an important factor which so far had not been known. Four healthy pregnant women with similar weight and gestational age and all with premature labor were administered a continuous intravenous infusion of 4 micrograms fenoterol/min. During and up to 24 hours after the end of the infusion, venous blood samples were taken in order to determine the fenoterol plasma concentrations by radioimmunoassay. From a steady state concentration (css) of 2242 +/- 391 pg/ml (x +/- S.E.), a non-linear two-phased plasma elimination was seen with half-lives t1/2 of 11.40 min and 4.87 h. The area under the plasma concentration-time curve (AUC0-12h) was 6.27 ng/ml x h. The total clearance (Cltot) was 114.8 l/h. These data are nearly the same as the data already known for healthy non-pregnant (male) volunteers. The deviations which are seen in the plasma concentrations in pregnant women in comparison to non-pregnant persons during or after continuous i.v. infusion can therefore not be caused by differences in the pharmacokinetics. Other factors, however, such as body weight and/or gestational age, might influence the results.
β2-拟交感神经药物非诺特罗（氢溴酸非诺特罗，CAS 1944 - 12 - 3，Partusisten）通常用于抑制子宫收缩（安胎）。对接受静脉或口服安胎治疗者的血浆浓度进行的研究，无论是在特定孕妇群体内部，还是与非孕妇相比，往往都显示出不同的结果。本研究的目的是确定非诺特罗在孕妇体内的药代动力学，这是一个迄今尚不明确的重要因素。四名体重和孕周相似且均有早产迹象的健康孕妇接受了4微克/分钟的非诺特罗持续静脉输注。在输注期间及结束后长达24小时内，采集静脉血样，通过放射免疫测定法测定非诺特罗的血浆浓度。从2242±391皮克/毫升（x±标准误）的稳态浓度（css）可以看出，血浆消除呈非线性双相，半衰期t1/2分别为11.40分钟和4.87小时。血浆浓度-时间曲线下面积（AUC0 - 12h）为6.27纳克/毫升·小时。总清除率（Cltot）为114.8升/小时。这些数据与健康非孕（男性）志愿者已知的数据几乎相同。因此，在持续静脉输注期间或之后，孕妇血浆浓度与非孕妇相比出现的偏差不可能是由药代动力学差异引起的。然而，其他因素，如体重和/或孕周，可能会影响结果。
