BACKGROUND: Preeclampsia is a major hypertensive disorder of pregnancy that may lead to severe complications, particularly in the first 2 weeks of the postpartum period. Blood pressure during the postpartum period remains high and often increases to levels higher than those observed during pregnancy. Furosemide, a fast-acting diuretic, reduces intravascular volume overload and may represent an alternative to accelerate the normalization of blood pressure levels. OBJECTIVE: This study aimed to evaluate the effectiveness of furosemide compared with a placebo for blood pressure control in the postpartum period in women with severe preeclampsia. STUDY DESIGN: In a triple-masked placebo-controlled randomized clinical trial, postpartum women with de novo preeclampsia with severe features or eclampsia diagnosed during pregnancy and adequate diuresis who had received magnesium sulfate were randomized to receive furosemide (40 mg/d orally for 5 days) or a placebo. The primary outcome was mean blood pressure. The secondary outcomes were frequency of severe hypertensive episodes, continued need for antihypertensives, number of antihypertensives used to control blood pressure, length of hospital stay, adverse effects, and maternal complications. A sample size of 120 patients was estimated, 60 in each arm of the study, based on the estimated difference between the mean systolic pressure of 142±12 mm Hg for the furosemide group and 153±19 mm Hg for the placebo group. RESULTS: Between June 20, 2014, and November 30, 2014, 271 women were screened, and 120 were randomized to the furosemide or placebo groups, of which 118 were included in the final analysis (58 in the furosemide group and 60 in the placebo group). Most characteristics were similar between the groups. The mean daily systolic and diastolic pressures were lower in the furosemide group (P<
.001), and there were fewer episodes of severe hypertension on the second (P=.04) and fifth (P=.04) days of the postpartum period. In addition, a shorter time was required until blood pressure was controlled (P=.01) in the furosemide group. CONCLUSION: Compared with placebo, 40 mg/d of oral furosemide in patients with preeclampsia reduced the mean daily systolic blood pressure in the first and fifth days of the postpartum period and mean daily diastolic blood pressure in the first, second, and fifth days of the postpartum period and the time required for blood pressure control.