What is the treatment for eclampsia?

Treatment of Eclampsia

Immediate Seizure Management

Magnesium sulfate is the first-line and definitive treatment for eclamptic seizures, administered immediately upon seizure onset. 1, 2, 3

Loading Dose Options

• Intravenous route (preferred): Administer 4-5g IV over 5 minutes 1, 2, 3
• Alternative combined IV/IM regimen: 4g IV loading dose immediately followed by 10g IM (5g in each buttock) for total loading dose of 14g 2
• IM-only regimen (when IV access unavailable): 5g IM in each buttock (10g total), then refer 2

Maintenance Therapy

• Continue magnesium sulfate at 1-2g/hour as continuous IV infusion 2, 3
• Alternative IM maintenance: 5g IM every 4 hours in alternating buttocks 4
• Duration: Continue for 24 hours after the last seizure or after delivery, whichever is later 2, 3

Critical Monitoring During Magnesium Administration

Monitor for magnesium toxicity by checking these parameters before each dose: 5, 4

• Patellar reflexes (knee jerk): Loss indicates toxicity at 3.5-5 mmol/L; withhold next dose if absent 5, 4
• Respiratory rate: Must be ≥16 breaths/minute; respiratory paralysis occurs at 5-6.5 mmol/L 5, 4
• Urine output: Maintain >100 mL over 4 hours preceding each dose 5
• Serum magnesium levels: Therapeutic range 2.5-7.5 mEq/L (3-6 mg/100 mL); cardiac arrest risk >12.5 mmol/L 5, 4

Have injectable calcium salt immediately available at bedside to counteract magnesium toxicity 5

Blood Pressure Management

Target blood pressure <160/105 mmHg to prevent maternal stroke and complications. 1, 2, 3

First-Line Antihypertensive Options

Labetalol IV (preferred in most guidelines): 1, 2

• Initial 20mg IV bolus
• Then 40mg after 10 minutes
• Followed by 80mg every 10 minutes for 2 additional doses
• Maximum cumulative dose: 220mg (do not exceed 800mg/24h to prevent fetal bradycardia) 1, 3

Nifedipine oral: 1

• 10mg PO, repeat every 20 minutes
• Maximum 30mg total
• Critical warning: Risk of precipitous hypotension when combined with magnesium sulfate 1, 3

Nicardipine IV: 1, 2

• Start at 5mg/h
• Increase by 2.5mg/h every 5-15 minutes
• Maximum 15mg/h

Second-Line Options

Hydralazine IV: 1

• 5mg IV bolus
• Then 10mg every 20-30 minutes
• Maximum 25mg, repeat in several hours as necessary

Agents to AVOID

Never use these medications: 3, 5

• Sublingual nifedipine: Risk of precipitous BP drop 3
• Sodium nitroprusside: Risk of fetal cyanide toxicity if used >4 hours 1, 3
• Diuretics: Plasma volume already reduced in preeclampsia 1, 3

Delivery Planning

Delivery is the only definitive cure for eclampsia and should occur after maternal stabilization. 1, 3

Timing of Delivery

Immediate delivery indicated for: 2

• Inability to control blood pressure despite two medications
• Progressive deterioration in liver function, creatinine, hemolysis, or platelet count
• Ongoing neurological features
• Placental abruption
• Abnormal fetal status
• Gestational age ≥37 weeks

Mode of Delivery

• Vaginal delivery is preferred unless cesarean indicated for obstetric reasons 1, 2
• Epidural anesthesia is favored but requires adequate fluid loading 1

Corticosteroids for Fetal Lung Maturation

Administer antenatal corticosteroids if gestational age ≤34 weeks 1, 2, 3

• Give over 48 hours to accelerate fetal lung maturation 1, 3
• May be given up to 38 weeks for elective cesarean 2
• Multiple courses not recommended 2

Monitoring Requirements

Maternal Monitoring

Continuous surveillance includes: 2

• Continuous blood pressure monitoring
• Deep tendon reflexes before each magnesium dose
• Respiratory rate (maintain ≥16/min)
• Urine output (>100 mL/4 hours)
• Serum magnesium levels

Laboratory tests twice weekly: 2

• Hemoglobin and platelet count
• Liver enzymes (AST, ALT)
• Creatinine
• Uric acid

Fetal Monitoring

Continuous fetal heart rate monitoring throughout treatment 2

• Ultrasound assessment of fetal biometry 2
• Amniotic fluid volume 2
• Umbilical artery Doppler 2

Common Pitfalls and Critical Warnings

Drug Interactions

Avoid combining magnesium sulfate with: 1, 2

• Calcium channel blockers (severe hypotension risk)
• Neuromuscular blocking agents (excessive neuromuscular block) 5
• CNS depressants including barbiturates and narcotics (additive depression) 5

Use extreme caution in digitalized patients: Magnesium can cause serious cardiac conduction changes and heart block 5

Renal Impairment

Magnesium is excreted solely by kidneys; use with extreme caution in renal impairment 5

• In severe renal impairment, do not exceed 20g magnesium in 48 hours 5
• Monitor serum magnesium levels closely 5

Fetal Considerations

Continuous magnesium administration beyond 5-7 days causes fetal harm: 5

• Hypocalcemia and skeletal demineralization in fetus 5
• Osteopenia and neonatal fractures reported 5
• Neonatal neuromuscular or respiratory depression if given >24 hours before delivery 5

Postpartum Management

Continue magnesium sulfate for 24 hours postpartum or after last seizure 2, 3

Continue antihypertensive therapy during labor and postpartum period 2

Switch from methyldopa to alternative antihypertensives postpartum 3

Follow-up at 6 weeks postpartum: 2

• Check blood pressure and urine
• Assess for secondary causes of hypertension in women <40 years with persistent hypertension

Counsel on future cardiovascular risk and recommend lifestyle modifications 3, 6