What is the role of Furosemide (Lasix) with potassium supplementation postpartum in the management of preeclampsia?

Medical Advisory BoardAll articles are reviewed for accuracy by our Medical Advisory Board
Educational purpose only • Exercise caution as content is pending human review
Article Review Status
Submitted
Under Review
Approved

Last updated: April 25, 2025View editorial policy

Personalize

Help us tailor your experience

Which best describes you? Your choice helps us use language that's most understandable for you.

From the Guidelines

Furosemide (Lasix) with potassium supplementation is recommended postpartum for women with preeclampsia to manage fluid retention and reduce blood pressure, with a typical regimen of furosemide 20-40 mg orally once or twice daily for 5-7 days, along with potassium chloride supplementation (typically 20-40 mEq daily) to prevent hypokalemia, as suggested by the International Society for the Study of Hypertension in Pregnancy guidelines 1.

Postpartum Management

The management of preeclampsia postpartum involves close monitoring of blood pressure, electrolytes, and urine output, with antihypertensives administered antenatally continued postpartum, and consideration given to diuretics like furosemide for fluid retention and hypertension management 1.

  • Monitoring of blood pressure should be done at least every 4 hours while awake, for at least 3 days postpartum, as preeclampsia may develop de novo intra- or early postpartum 1.
  • General well-being and neurological status should also be monitored, with repeat laboratory tests (Hb, platelets, creatinine, liver transaminases) the day after delivery and then second daily until stable if any of these were abnormal before delivery 1.

Treatment Considerations

The use of furosemide with potassium supplementation helps mobilize excess fluid accumulated during pregnancy, preventing potassium depletion, a common side effect of loop diuretics, and is particularly beneficial for women with significant edema, hypertension that persists after delivery, or pulmonary congestion.

  • Treatment should begin after delivery once the patient is hemodynamically stable, usually within 24-48 hours postpartum, with potassium levels checked before starting therapy and monitored during treatment, and dose adjustments made accordingly 1.
  • The diuretic effect helps reduce peripheral edema, pulmonary congestion, and hypertension by decreasing intravascular volume, with treatment duration typically short-term until excess fluid is eliminated and blood pressure normalizes.

Key Considerations

  • Avoid NSAIDs in women with preeclampsia if possible, especially in the setting of acute kidney injury (AKI), and use alternative pain relief 1.
  • Most women can be discharged by day 5 postpartum, especially when they are able to monitor their blood pressure at home, with antihypertensives restarted after delivery and tapered slowly only after days 3 to 6 postpartum unless blood pressure becomes low (<110/70 mm Hg) or the woman becomes symptomatic in the meantime 1.

From the FDA Drug Label

The FDA drug label does not answer the question.

From the Research

Postpartum Management of Preeclampsia with Lasix and Potassium

  • The use of furosemide (Lasix) in the postpartum management of preeclampsia has been studied in several trials 2, 3, 4.
  • A randomized clinical trial published in 2005 found that brief postpartum furosemide therapy for patients with severe preeclampsia enhanced recovery by normalizing blood pressure more rapidly and reducing the need for antihypertensive therapy 2.
  • Another study published in 2025 found that 40 mg/day of oral furosemide in patients with preeclampsia in the postpartum period reduced mean daily systolic blood pressure and the time required until blood pressure was controlled 3.
  • A randomized controlled trial published in 2017 found that the use of a short course of furosemide along with nifedipine significantly reduced the need for additional antihypertensive in severe preeclamptic women with postpartum hypertension 4.

Potassium Supplementation

  • The study published in 2005 mentioned that patients received oral potassium supplementation along with furosemide 2.
  • However, the other studies did not provide detailed information on potassium supplementation 3, 4.
  • It is essential to note that potassium supplementation is crucial when using furosemide to prevent hypokalemia.

Diagnosis and Management of Postpartum Preeclampsia

  • Postpartum preeclampsia is a separate entity from preeclampsia with antepartum onset, and its diagnosis should be considered in women with new-onset hypertension 48 hours to 6 weeks after delivery 5.
  • The cornerstones of treatment for postpartum preeclampsia include the use of antihypertensive agents, magnesium, and diuresis 5.
  • The use of furosemide in the postpartum management of preeclampsia is supported by several studies, which found that it can help reduce blood pressure and the need for additional antihypertensive therapy 2, 3, 4.

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

Have a follow-up question?

Our Medical A.I. is used by practicing medical doctors at top research institutions around the world. Ask any follow up question and get world-class guideline-backed answers instantly.