Effect of clonidine on pregnant uterine contractions an experimental and a clinical study

ABSTRACT

The effect of clonidine HCl on the pregnant mouse uterus was studied in vitro. Contra-recorded using physiograph six-E.M. Clonidine HCl at three dose levels 0.06, 0.3 and 0.6 mcg/ml did not significantly affect the mean amplitude [MA] or the mean frequency [MF] of the contracted uterine segments. Administration of oxytocin increased significantly the MA of the contractions while the MF was not significantly different also produced by the combined administration of oxytocin and clonidine. In the clinical study the influence of 1.0 mcg/kg IM clonidine HCl on human uterine activity was studied by external tocograhy in 15 women at the end of a normal pregnancy. For women in spontaneous labour [n=9] and in women in whom uterine contractions were augmented by oxytocin infusion [n - 6] no change was observed in the frequency or duration of uterine contractions as a result of clonidine administration. Clonidine did not have any noticeable effect on base line foetal heart rate, long term variability number of accelerations and type of decelerations. No serious side effects were observed either in the mother or neonate. Additional work with this compound in obstetrics is merited in view of its potential advantages especially in hypertensive patients