RITODRINE AND NIFEDIPINE AS TOCOLYTIC AGENTS - A PRELIMINARY COMPARISON

The effectiveness of the tocolytic agent and other betamimetic drugs i n the treatment of preterm labor remains controversial. Effectiveness or efficancy of ritodrine has not yet convincingly been proven. A majo r concern are the marked side effects of beta-mimetics. The calcium ch annel blocker nifedipine has been used for tocolysis shortly after its introduction in clinical practice and is considered to be a probable good alternative for ritodrine. The efficacy of nifedipine versus rito drine in the treatment of preterm labor was assessed in a retrospectiv e study. 32 patients received intravenous ritodrine and 29 oral nifedi pine. As endpoints were used: postponement of delivery, maternal side effects and perinatal outcome. The results of this retrospective study suggest that nifedipine is more successful in postponing delivery tha n ritodrine. Maternal side effects seemed to occur more frequently and be more serious in patients treated with ritodrine as compared to nif edipine. Perinatal outcome seemed better in the nifedipine group than in the ritodrine group. The promising data from small prospective stud ies and the results of this retrospective study warrant further large prospective studies on the definive place of nifedipine in the treatme nt of premature labor. Until the results of such a trial are available we advocate the use of nifedipine in case of preterm labor, especiall y in a patient with diabetes mellitus, ruptured membranes, cardiac dis ease or multiple pregnancy, in order to avoid the characteristic side effects of beta-mimetics.