What is the treatment for eclampsia?

Treatment of Eclampsia

Immediate administration of intravenous magnesium sulfate is the definitive treatment for eclampsia, combined with urgent blood pressure control using IV labetalol or nicardipine, followed by delivery after maternal stabilization. 1, 2

Immediate Seizure Management

Magnesium sulfate is the only anticonvulsant that should be used for eclampsia—it is superior to diazepam, phenytoin, and all other anticonvulsants for both treating active seizures and preventing recurrence. 2, 3, 4, 5

Magnesium Sulfate Dosing

IV regimen (preferred):

• Loading dose: 4-5 g IV over 5 minutes 2, 6
• Maintenance: 1-2 g/hour continuous IV infusion 2, 6
• Duration: Continue for 24 hours after delivery OR last seizure, whichever is later 2, 7

Alternative IM regimen (when IV pumps unavailable):

• Loading dose: 4 g IV over 5 minutes PLUS 10 g IM (5 g in each buttock) 2
• Maintenance: 5 g IM every 4 hours in alternating buttocks 2, 8

Critical Monitoring for Magnesium Toxicity

Monitor these parameters before each dose and continuously during infusion 6, 8:

• Patellar reflexes: Loss of deep tendon reflexes indicates impending toxicity (occurs at 3.5-5 mmol/L) 6, 8
• Respiratory rate: Must be ≥16 breaths/minute; respiratory paralysis occurs at 5-6.5 mmol/L 6, 8
• Urine output: Must be ≥100 mL over 4 hours (or >35 mL/hour) 2, 6
• Therapeutic serum level: 2.5-7.5 mEq/L (or 3-6 mg/100 mL) 6, 8

Have calcium gluconate immediately available at bedside to reverse magnesium toxicity—cardiac arrest can occur at levels >12.5 mmol/L. 6, 8

Blood Pressure Management

Target blood pressure: <160/105 mmHg (ideally systolic 110-140 mmHg and diastolic 85 mmHg). 1, 2

First-Line IV Antihypertensives

Labetalol (preferred in most guidelines):

• 20 mg IV bolus initially
• Then 40 mg after 10 minutes
• Then 80 mg every 10 minutes
• Maximum total dose: 220 mg 1, 2

Nicardipine (alternative):

• Start at 5 mg/hour IV
• Increase by 2.5 mg/hour every 5-15 minutes
• Maximum: 15 mg/hour 1, 2

Hydralazine (second-line option):

• Use when labetalol/nicardipine unavailable 1
• Note: Found to be inferior to other agents in some studies 1

Critical Caveat on Magnesium-Nifedipine Interaction

Avoid combining magnesium sulfate with calcium channel blockers (especially nifedipine)—this combination causes severe hypotension and potential cardiovascular collapse. 2, 6

Fluid Management

Restrict total fluid intake to 60-80 mL/hour to prevent pulmonary edema—eclamptic women have capillary leak and reduced plasma volume. 2, 7

Diuretics are absolutely contraindicated because plasma volume is already reduced in eclampsia. 1, 9

For pulmonary edema specifically: Use IV nitroglycerin starting at 5 mcg/min, gradually increased every 3-5 minutes to maximum 100 mcg/min. 1, 7

Delivery Planning

Delivery is the only definitive cure for eclampsia—plan for delivery after maternal stabilization with magnesium sulfate and blood pressure control. 1, 2

Absolute Indications for Immediate Delivery

Proceed with delivery immediately if any of the following occur 2, 7:

• Inability to control blood pressure despite ≥3 antihypertensive classes
• Progressive deterioration in liver function, creatinine, or platelet count
• Ongoing neurological symptoms despite treatment
• Pulmonary edema
• Non-reassuring fetal status
• Placental abruption
• Gestational age ≥37 weeks

Timing Based on Gestational Age

• ≥37 weeks: Deliver after stabilization 2, 7
• 34-37 weeks: Expectant management acceptable if stable; deliver if any deterioration 2, 7
• <34 weeks: Give corticosteroids for fetal lung maturation (if time permits), then deliver after stabilization 1, 2

Vaginal delivery is preferred unless cesarean section is indicated for obstetric reasons. 2, 9

Postpartum Management

Continue magnesium sulfate for 24 hours postpartum or 24 hours after the last seizure, whichever is later—25-30% of eclamptic seizures occur postpartum. 2, 7, 9

Monitor blood pressure every 4-6 hours for at least 3 days postpartum and continue antihypertensive therapy. 2

Avoid NSAIDs in women with eclampsia, especially if acute kidney injury is present—use alternative analgesia. 2

Common Pitfalls to Avoid

• Never use sodium nitroprusside except as absolute last resort—it causes fetal cyanide toxicity 2, 7
• Never use ACE inhibitors or ARBs—they cause fetal renal dysgenesis 1, 9
• Never give magnesium sulfate if reflexes are absent—this indicates toxicity 6, 8
• Never use short-acting oral nifedipine with magnesium—risk of uncontrolled hypotension 7
• Never delay delivery beyond stabilization—eclampsia can rapidly deteriorate despite treatment 2, 7