Does intravenous ritodrine therapy cause capillary endothelial damage?

The effects of intravenous (IV) ritodrine therapy on capillary endothelial damage and colloid osmotic pressure were examined in 15 patients in premature labor. Plasma fibronectin, a marker for capillary endothelial damage, did not change significantly after IV ritodrine therapy. Plasma colloid osmotic pressure was lowered following ritodrine therapy (P less than 0.05). Pretreatment plasma fibronectin levels in the study and control groups were similar. Interestingly, pretreatment colloid osmotic pressure in the study group was significantly lower than that of the control group (P less than 0.05). Our data suggest that there is no evidence of capillary endothelial damage following ritodrine therapy. Lower levels of plasma colloid osmotic pressure in patients with preterm labor, which are further reduced with IV ritodrine therapy, may predispose these patients to pulmonary edema.