Acta obstetricia et gynecologica Scandinavica
-
Acta Obstet Gynecol Scand · Sep 2002
Effect of magnesium sulfate, isradipine, and ritodrine on contractions of myometrium: pregnant human and rat.
Magnesium sulfate, isradipine, and ritodrine are smooth muscle relaxants used for treating preterm labor. The aim of this study is to investigate the action profile of these drugs on the amplitude and frequency of spontaneous contractions of isolated myometrial strips of pregnant human and rat. ⋯ Because of tachyphylaxis, the effectiveness of ritodrine is limited for inhibition of myometrial contractions. Magnesium sulfate reduced the frequency of spontaneous contractions without affecting the amplitude. Isradipine may be an interesting therapeutic alternative in situations where inhibition of uterine activity is desirable.