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Randomized Controlled Trial
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Korean J Obstet Gynecol. 2002;45(12):2153-2157. Published online December 1, 2002.
- Oral Nicardipine Versus Intravenous Ritodrine for the Treatment of Preterm Labor.
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Tae Bok Song, Yoon Ha Kim, Jin Choi, Woo Dai Kang, Yoon Sang Oh, Myoung Seon Kang, Moon Kyoung Cho
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1Department of Obstetrics and Gynecology, Chonnam National University Medical School, Korea.
2Chonnam National University Research Institute of Medical Sciences, Gwangju, Korea.
- Abstract
- OBJECTIVE
This study was conducted to compare the efficacy and safety of oral nicardipine in acute therapy for preterm labor with those of parenteral ritodrine hydrochloride. METHODS: Patients between 24 and 34 weeks' gestation with documented preterm labor were randomly assigned to receive oral nicardipine (n=31) or intravenous ritodrine (n=32) as initial tocolytic therapy. Patients in the nicardipine group received a 40-mg loading dose and then 20 mg every 2 hours as needed to stop contractions (total 80 mg). Patients in the ritodrine group received a 0.05 mg/min as initial dose. The dose was increased at 15-minute intervals until uterine contractions were inhibited or side effects became intolerable. The maximum recommended dose was 0.35 mg/min. Patients could be switched to another tocolytic regimen if they continued to have contractions after 6 hours of therapy. The main outcome variables examined were failure of tocolysis, time to uterine contractions equal or less than 5 times per hour, time to uterine quiescence, time gained in utero, and frequency of adverse medication effects. RESULTS: There were no significant differences in maternal demographic characteristics between the groups. Successful tocolysis, defined as cessation of uterine contractons less than 6 hours from initial dose, was observed in 58.1% in the nicardipine group and 65.6% in the ritodrine group (P=.544). Among patients with successful tocolysis who responded with uterine quiescence within 6 hours, there was no significant difference in the time to uterine quiescence in the ritodrine group (P=.087). Time to uterine contractions equal or less than 5 times per hour from initial treatment showed no significant difference between the two groups with successful tocolysis (P=.097). The patients in the ritodrine hydrochloride group had more adverse side effects, mainly maternal tachycardia (P=.013) and nausea and/or vomiting (P=.006). CONCLUSION: Oral nicardipine was effective, safe, and well-tolerated tocolytic agent. Patients who received ritodrine hydrochloride were more likely to have adverse medication effects.
Keywords :Preterm labor;nicardipine;ritodrine hydrochloride
