Effectiveness and safety of ritodrine hydrochloride for the treatment of preterm labour: a systematic review.

PURPOSE To analyse the available data on the effectiveness and safety of ritodrine hydrochloride in delaying delivery and in decreasing the incidence of preterm birth. METHODS Systematic review of randomised controlled trials (RCTs) that compared the effectiveness and safety of ritodrine hydrochloride with a placebo or with no treatment. Main outcome measures were relative risks (RRs) for perinatal mortality, neonatal respiratory distress syndrome (RDS), delivery within 48 hours or 7 days, preterm birth before 37 weeks gestation and low birth weight. We searched computerised databases (MEDLINE, CENTRAL, Ichushi Web) from their inception to October 2004, and searched the references of eligible trials. RESULTS Seventeen RCTs were included and meta-analysis was conducted. Pooled RRs relative to placebo for delivery within 48 hours or 7 days for parenteral ritodrine hydrochloride were 0.74 (95%CI (confidential interval): 0.56, 0.97), 0.85 (95%CI: 0.74, 0.97). There was no significant decrease in perinatal mortality, the proportion of RDS, preterm birth and low birth weight infants. Maternal side-effects significantly increased in patients receiving ritodrine with respect to those receiving a placebo. Pooled RRs relative to placebo for oral ritodrine hydrochloride showed no significant decrease in primary and secondary endpoints. CONCLUSIONS The effectiveness of parenteral ritodrine hydrochloride for tocolysis in preterm labour is limited to short-range prolongation of gestation. The effectiveness of maintenance tocolytic therapy with oral ritodrine hydrochloride was not proved.