What medication should be given to a pregnant woman experiencing an epileptic seizure?

Acute Seizure Management in Pregnant Women

Administer intravenous lorazepam 4 mg at 2 mg/min as the immediate first-line treatment for any pregnant woman actively seizing, followed by fosphenytoin or levetiracetam as second-line therapy if seizures continue. 1

First-Line Treatment: Benzodiazepines

• Lorazepam is the preferred benzodiazepine with 65% efficacy in terminating status epilepticus and superior performance compared to diazepam (59.1% vs 42.6% seizure termination). 1

• Administer lorazepam 4 mg IV at 2 mg/min as the immediate intervention for active seizures. 1

• Alternative benzodiazepine options if IV access is unavailable include:

  • IM midazolam (effective in prehospital settings) 1
  • Intranasal midazolam 1
  • Rectal diazepam 0.5 mg/kg up to 20 mg (though absorption may be erratic) 2

• Have airway equipment immediately available before administering any benzodiazepine, as respiratory depression can occur, particularly in pregnancy where functional residual capacity is already decreased. 1

Critical Immediate Actions

• Check fingerstick glucose immediately and correct hypoglycemia—a rapidly reversible cause of seizures. 1

• Simultaneously search for reversible causes including hypoglycemia, hyponatremia, hypoxia, drug toxicity, CNS infection, stroke, intracerebral hemorrhage, and withdrawal syndromes. 1

• Do not delay treatment for neuroimaging—CT scanning can be performed after seizure control is achieved and the patient is stabilized. 1

Second-Line Treatment (If Seizures Continue After Benzodiazepines)

If the pregnant patient continues seizing after adequate benzodiazepine dosing, immediately escalate to one of the following second-line agents: 1

Preferred Options for Pregnancy:

• Levetiracetam 30 mg/kg IV (approximately 1000-2000 mg) over 5 minutes

  • 68-73% efficacy in benzodiazepine-refractory status epilepticus 1
  • Minimal cardiovascular effects and no hypotension risk 1
  • No cardiac monitoring requirements, making it particularly suitable for pregnant patients 1
  • Can be administered rapidly without the cardiac risks associated with phenytoin 1

• Valproate 20-30 mg/kg IV over 5-20 minutes

  • 88% efficacy with 0% hypotension risk 1
  • Superior safety profile compared to fosphenytoin (0% vs 12% hypotension) 1
  • However, valproate has significant teratogenic risks and should be avoided in pregnancy when possible 2

• Fosphenytoin 20 mg PE/kg IV at maximum rate of 50 mg/min

  • 84% efficacy but 12% hypotension risk requiring continuous cardiac monitoring 1
  • Requires continuous ECG and blood pressure monitoring due to cardiovascular risks 1
  • Traditional and most widely available second-line agent, with 95% of neurologists recommending phenytoin/fosphenytoin for benzodiazepine-refractory seizures 1

Important Pregnancy-Specific Considerations:

• Phenytoin/fosphenytoin carries teratogenic risks including increased incidence of major malformations (orofacial clefts, cardiac defects), fetal hydantoin syndrome, and approximately 2.4-fold increased risk for any major malformation. 3

• Despite teratogenic potential, there is definitely less risk to the fetus from anticonvulsant exposure than from uncontrolled seizures. 4

• Good fetal outcome is dependent on rapid seizure control—the priority is stopping the seizure immediately. 4

• Phenytoin pharmacokinetics change significantly during pregnancy, with total concentrations falling but free (active) concentrations remaining relatively adequate for carbamazepine and phenytoin. 5

Refractory Status Epilepticus (If Seizures Continue Despite Second-Line Agent)

Refractory status epilepticus is defined as seizures continuing despite benzodiazepines and one second-line agent. 1

• Initiate continuous EEG monitoring at this stage. 1

Third-Line Anesthetic Agents:

• Midazolam infusion (first-choice anesthetic agent):

  • Loading dose: 0.15-0.20 mg/kg IV 1
  • Continuous infusion: 1 mg/kg/min, titrate up by 1 mg/kg/min every 15 minutes to maximum 5 mg/kg/min 1
  • 80% overall success rate with 30% hypotension risk 1
  • Load with phenytoin/fosphenytoin, valproate, levetiracetam, or phenobarbital during the midazolam infusion to ensure adequate levels of long-acting anticonvulsants before tapering. 1

• Propofol:

  • 2 mg/kg bolus, then 3-7 mg/kg/hour infusion 1
  • 73% seizure control rate 1
  • Requires mechanical ventilation but shorter ventilation time than barbiturates (4 days vs 14 days) 1
  • 42% hypotension risk (less than pentobarbital's 77%) 1

• Pentobarbital (most effective but highest risk):

  • 13 mg/kg bolus, then 2-3 mg/kg/hour infusion 1
  • 92% efficacy but 77% hypotension risk 1

Critical Pitfalls to Avoid

• Never use neuromuscular blockers alone (such as rocuronium)—they only mask motor manifestations while allowing continued electrical seizure activity and brain injury. 1

• Do not skip to third-line agents until benzodiazepines and a second-line agent have been tried. 1

• Do not delay anticonvulsant administration for neuroimaging in active status epilepticus. 1

• Avoid valproate in pregnancy when alternatives exist due to major teratogenic risks, though it may be necessary if other agents fail. 2

• Monitor for respiratory depression with all benzodiazepines, especially given pregnancy-related decreased functional residual capacity. 2, 1

Post-Seizure Management

• Administer vitamin K to the mother before delivery and to the neonate after birth to prevent potentially life-threatening bleeding disorder related to decreased vitamin K-dependent clotting factors from phenytoin exposure. 3

• Measure free (unbound) phenytoin concentrations rather than total concentrations during pregnancy for more effective clinical management, as total concentrations fall significantly but free concentrations may remain adequate. 5

• Postpartum restoration of the original antiepileptic drug dosage will probably be indicated, as pregnancy-induced pharmacokinetic changes reverse after delivery. 3