RITODRINE HYDROCHLORIDE - A BETA-MIMETIC AGENT FOR USE IN PRETERM LABOR .2. EVIDENCE OF EFFICACY

Abstract

In a multicenter series of randomized prospective double-blind controlled studies, ritodrine hydrochloride was compared with ethanol or placebo in treatment of idiopathic pretern labor. When compared with controls, there was, among offspring of ritodrine-treated mothers, a significantly reduced incidence of neonatal death and respiratory distress syndrome (P < 0.05 in both comparisons) and a significantly higher proportion of infants achieving 36 wk gestation (P < 0.05) or birth weight > 2500 g (P < 0.05). There was a significant improvement in gestational age at delivery (P < 0.05) and in the number of days gained in utero (P < 0.001) among ritodrine-treated patients as compared with controls. These results, coupled with a finding of generally acceptable side effects, contributed to ritodrine''s becoming the 1st drug approved for the treatment of pretern labor in the USA.