Obstetrics

Magnesium Sulfate Obstetric Dosing & Toxicity Protocol (ACOG Preeclampsia / Eclampsia)

Calculates loading/maintenance dosing, fetal neuroprotection rates, and Calcium Gluconate antidote protocols.

Parameters

Magnesium Sulfate Obstetric Dosing & Toxicity Protocol (ACOG Preeclampsia / Eclampsia) Result

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FormulaLoading Dose = 4.0–6.0 g IV over 15–20 min Maintenance Infusion = 1.0–2.0 g/hour IV (1.0 g/hr if Cr > 1.0 or Urine < 30 mL/hr) Therapeutic Serum Range: 4.8–8.4 mg/dL (2.0–3.5 mmol/L) Antidote = 1.0 g IV Calcium Gluconate 10% (10 mL over 3–5 min)

Clinical Pearls

The definitive life-saving therapy reducing eclamptic seizure risk by > 50% and maternal mortality in severe preeclampsia.

Limitations

Contraindicated in myasthenia gravis (precipitates acute myasthenic crisis/respiratory arrest) and high-grade atrioventricular heart block.