Tocólisis con clorhidrato de isoxuprina o nifedipina en la amenaza de parto pretérmino

objective: to compare the efficacy of isoxuprine clorhidrate or nifedipine in tocolysis of threatened preterm labor. methods: 82 patients with a gestational age between 24 and 34 weeks and threatened preterm labor diagnosis were selected. patients were randomly divided in 2 groups to receive isoxuprine clorhidrate (group a) or nifedipine (group b). time of cease of contractions, maternal blood pressure, glucose concentrations and maternal adverse effects were determined. setting: maternidad "dr. nerio belloso", hospital central "dr. urquinaona", maracaibo. estado zulia. results: an effective tocolysis was obtained within 24 hours in 61.0 % and 70.7 % for patients in group a and b, respectively (p = ns). after 7 days of treatment, 36.6 % of patients in group a and 31,7 % of patients in group b were still without contractions (p = ns). a delay in labor till 34 weeks or more was made in 26.8.% and 29.3 % of patients in group a and b, respectively. in the group of patients treated with isoxuprine clorhidrate a significant raise of glucose concentrations was observed (p < 0.001). maternal adverse effects were significant more frequent in isoxuprine clorhidrate group after 2 and 24 hours of treatment (p < 0,05). conclusion: nifedipine has a similar effectivity than isoxuprine clorhidrate for tocolysis in threatened preterm labor and produces less adverse effects.