title: Hemodynamic and metabolic effects after nifedipine and ritodrine tocolysis.
abstract: OBJECTIVE
  The purpose of this study is to compare the hemodynamic and metabolic changes after ritodrine and nifedipine tocolysis.
  
  
  METHODS
  For an open randomized study, patients with preterm labor (N=185) were allocated to groups to receive ritodrine intravenously (N=90) or nifedipine orally (N=95).
  
  
  RESULTS
  The mean diastolic blood pressure was significantly lower in the ritodrine group 24 h (65+/-12 vs. 70+/-8, P=0.001) and 48 h (65+/-12 vs. 71+/-8, P=0.004) after starting tocolysis compared with the nifedipine group. Mean maternal heart rate was significantly higher in the ritodrine group 24 h (105+/-17 vs. 86+/-13, P<0.0001) and 48 h (100+/-21 vs. 85+/-12, P<0.0001) after starting tocolysis compared with the nifedipine group. Mean fasting glucose levels were higher (6.68+/-2.53 vs. 4.93+/-1.23, P=0.0016), while mean potassium levels were lower (3.52+/-0.84 vs. 3.81+/-0.45, P=0.04) in the ritodrine group 48 h after starting tocolysis compared with the nifedipine group.
  
  
  CONCLUSIONS
  Use of nifedipine for preterm labor is associated with a lower incidence of adverse hemodynamic and metabolic changes compared with ritodrine after 24 and 48 h of tocolysis. In our opinion nifedipine is the preferred drug of choice for the treatment of preterm labor.
authors.affiliation: Department of Obstetrics and Gynecology, Free University Hospital Amsterdam, Amsterdam, The Netherlands. hoog.pap@wxs.nl
authors.forename: D N M
authors.initials: DN
authors.lastname: Papatsonis
authors.forename: H P
authors.initials: HP
authors.lastname: van Geijn
authors.forename: O P
authors.initials: OP
authors.lastname: Bleker
authors.forename: H J
authors.initials: HJ
authors.lastname: Adèr
authors.forename: G A
authors.initials: GA
authors.lastname: Dekker
mesh_terms: D000328:Adult; D015331:Cohort Studies; D005260:Female; D005947:Glucose / Q000378:metabolism; D006439:Hemodynamics / Q000187:drug effects*; D006801:Humans; D008660:Metabolism / Q000187:drug effects*; D009543:Nifedipine / Q000494:pharmacology* / Q000627:therapeutic use; D007752:Obstetric Labor, Premature / Q000188:drug therapy*; D011188:Potassium / Q000378:metabolism; D011247:Pregnancy; D012312:Ritodrine / Q000494:pharmacology* / Q000627:therapeutic use; D015149:Tocolytic Agents / Q000494:pharmacology* / Q000627:therapeutic use
chemical_list: D015149:Tocolytic Agents; D012312:Ritodrine; D009543:Nifedipine; D005947:Glucose; D011188:Potassium