From the Guidelines
For a pregnant patient experiencing seizure activity, the next best step is to administer intravenous magnesium sulfate, particularly if the seizure is related to eclampsia. The typical loading dose is 4-6 grams IV over 15-20 minutes, followed by a maintenance infusion of 1-2 grams per hour, as recommended by the ISSHP guidelines 1. Magnesium is the first-line treatment for eclamptic seizures as it stabilizes neuronal membranes and reduces cerebral irritability.
Key Considerations
- The choice between magnesium and antiepileptic drugs depends on whether the seizure is eclampsia-related or due to epilepsy, with magnesium being preferred for eclampsia and benzodiazepines (like lorazepam 2-4 mg IV) being the initial treatment for non-eclamptic seizures.
- For seizures due to epilepsy during pregnancy, lamotrigine is generally considered one of the safer antiepileptic medications, but it would not be the immediate treatment for an active seizure.
- In acute seizure management, ensuring airway patency, administering oxygen, placing the patient in left lateral position to prevent aortocaval compression, and monitoring vital signs are also critical steps.
- Blood pressure management is essential if hypertension is present, aiming to maintain BP 110 to 140/85 mm Hg, as suggested by the ISSHP guidelines 1.
Management of Eclampsia
- The ISSHP recommends that all preeclamptic women in LMICs should receive MgSO4, as the cost-benefit is greatest, and approximately 100 women need MgSO4 to prevent 1 seizure 1.
- The dosing regimens used in the Eclampsia and MAGPIE trials should be used, with a loading dose of 4 grams IV and 5 g in one buttock and another 5 g in the other buttock, followed by a maintenance dose of 5 g every 4 hours for 24 hours in alternate buttocks 1.
From the FDA Drug Label
In Pre-eclampsia or Eclampsia In severe pre-eclampsia or eclampsia, the total initial dose is 10 to 14 g of magnesium sulfate. For controlling seizures associated with epilepsy, glomerulonephritis or hypothyroidism, the usual adult dose is 1 g administered IM or IV A serum magnesium level of 6 mg/100 mL is considered optimal for control of seizures.
The next best step for treating a seizure in a pregnant patient is to administer magnesium sulfate. The usual dose is 1 g administered IM or IV for controlling seizures, and a serum magnesium level of 6 mg/100 mL is considered optimal for control of seizures 2. Lamotrigine is not mentioned in the provided drug labels as a treatment for seizures in pregnant patients.
From the Research
Treating Seizures in Pregnant Patients
- The next best step in treating a seizure in a pregnant patient involves considering the use of magnesium sulfate or other anticonvulsants.
- According to 3, magnesium sulphate is the drug of choice for treating eclampsia and has been shown to more than halve the risk of eclampsia.
- Additionally, 4 states that magnesium sulfate is the drug of choice for the prevention and control of maternal seizures in patients with severe preeclampsia or eclampsia during the peripartum period.
Comparison with Other Anticonvulsants
- 3 compared magnesium sulphate with other anticonvulsants, such as phenytoin and nimodipine, and found that magnesium sulphate reduced the risk of eclampsia.
- However, 5 notes that magnesium sulfate is contraindicated in patients with myasthenia gravis, and alternative anticonvulsants such as levetiracetam may be used instead.
Safety and Efficacy of Magnesium Sulfate
- 6 conducted an integrative review of the literature and found that the incidence of severe adverse reactions to magnesium sulfate is low, with an overall rate of absent patellar reflex of 1.6% and respiratory depression of 1.3%.
- 7 also supports the use of magnesium sulfate for patients with severe features of preeclampsia, not only for women with neurological symptoms, and presents a comprehensive algorithm for managing patients with preeclampsia with severe features.
Alternative Options
- 4 mentions that alternative antihypertensive agents, such as labetalol, may provide additional benefit in the management of hypertension for preeclamptic patients.
- 5 describes the effective use of levetiracetam and various antihypertensive medications, including intravenous labetalol, in a patient with myasthenia gravis who developed severe preeclampsia.