The use of nifedipine during the postpartum period in patients with severe preeclampsia.

Nifedipine is a calcium channel blocker that reduces blood pressure and increases renal blood flow. This double-blind investigation evaluated the effect of nifedipine in postpartum patients with severe preeclampsia. Thirty-one patients were randomized to receive either nifedipine (10 mg) or placebo every 4 hours beginning immediately after delivery. Data analysis revealed a significantly higher urine output in the nifedipine group during the first 24 hours after delivery (3834 versus 2057 ml; p less than 0.05). A significant reduction in mean arterial pressure was also noted in the nifedipine group between 18 and 24 hours postpartum (93.9 versus 100.2 mm Hg; p less than 0.05). There were no significant differences in the systolic or diastolic blood pressures, pulse, laboratory study results, or the need to administer hydralazine to control blood pressure. Nifedipine appears to have a beneficial effect on urinary output and mean arterial pressure during the first 24 hours post partum in patients with severe preeclampsia.