Ritodrine in the treatment of preterm labour: a study of 213 patients

Abstract

In a study of 213 patients with diagnosed, uncomplicated preterm labour up to 33 weeks gestation, intravenous followed by oral ritodrine (Yutopar) was found to be an effective treatment. Success rate was related to Bishop score at commencement of therapy, the mean time to delivery being 36.9 days. It was 2 5 6 days in 26.5% of patients and 3 2 days in 9 1%. Relapse rate was low if infusion was followed by an adequate

The effect of prenatal administration of dexamethasone and ritodrine on cord blood cortisol and glucose concentrations in premature infants with respiratory distress syndrome

“…Our findings confirm the studies of others [4, 6,11] that concomitant antepartum administration of glucocorticoids and beta-mimetics can significantly reduce the incidence and severity of RDS in premature infants. The reduction in the incidence of RDS was particularly marked at less than 33 weeks gestation, but was also lower in those delivered at 33 to 36 weeks, although in them the difference was not statistically significant.…”

“…Thus, they are often administered concomitantly to prevent preterm delivery and also the respiratory distress syndrome (RDS) of prematurity [4, 6,11]. The fetal metabolic effects of beta-adrenergic drugs such as ritodrine during pregnancy have not been thoroughly evaluated, and there are few studies in which these agents were administered simultaneously with glucocorticoids [4, 6,11]. The purpose of our investigation was to determine the effects of the combined use of maternal glucocorticoids and beta-adrenergic drugs on umbilical cord plasma cortisol and capillary serum glucose concentrations in the premature infant, and on the incidence of RDS in these infants.…”

Prenatal maturation, the timing of birth and how it may be regulated in domestic animals

“…Sympatho-adrenal activity, and particularly the release of adrenaline, will result in myometrial relaxation under the influence of fl-receptor stimulation (Nathanielsz, 1985). Indeed fl-agonists are frequently used in obstetric practice in order to prevent or retard preterm labour (Downey & Martin, 1982). On the other hand, there is some evidence for the development of uterine a-receptors at the tubal ends of the uterine horns (Arkinstall & Jones, 1988).…”

Preterm ruptured membranes, no contractions

“…Levy and Warsof (1985) found some prolongation of the latent period between membrane rupture and onset of labour using ritodrine, 10 mg 4 hourly, but it is difficult to see how effective levels of ritodrine could be obtained by oral administration. Even the large and frequent doses used in the later stages of our trial only produce serum levels of the order of one fifth of the minimum levels usually considered effective with intravenous use (Post, 1978;Downey and Martin, 1983;Lamont and Elder, 1986).…”