Hemodynamic and metabolic effects after nifedipine and ritodrine tocolysis.
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.
Papatsonis
D N M
DN
Department of Obstetrics and Gynecology, Free University Hospital Amsterdam, Amsterdam, The Netherlands. hoog.pap@wxs.nl
van Geijn
H P
HP
Bleker
O P
OP
Adèr
H J
HJ
Dekker
G A
GA
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
D015149:Tocolytic Agents; D012312:Ritodrine; D009543:Nifedipine; D005947:Glucose; D011188:Potassium