Maternal morbidity associated with isoxsuprine and terbutaline tocolysis

A retrospective study of 343 women treated with isoxsuprine and/or terbutaline for preterm labor (PTL) was performed to determine the incidence and nature of maternal morbidity which is associated with this treatment. The incidence of mild cardiovascular (CV), neurological and gastrointestinal side effects was similar with both medications. The incidence, however, of severe CV complications such as pulmonary edema and myocardial ischemia was higher among women treated with i.v. terbutaline (5.3%) than among those treated with isoxsuprine (0.8%, P less than 0.05). Patients with multiple gestations on i.v. terbutaline therapy had an exceptionally high incidence of severe CV complications (43%), while none of the twin pregnancies on i.v. isoxsuprine had such complications. Corticosteroid treatment was not associated with a significant increase of complications with either tocolytic medication. Both medications had similar success in inhibiting PTL.