Magnesium sulfate is an inorganic salt with the formula MgSO₄, commonly used in clinical medicine as an intravenous or intramuscular medication.
It is primarily indicated for the prevention and treatment of seizures in preeclampsia and eclampsia, for fetal neuroprotection in imminent preterm birth, and as adjunctive therapy in severe asthma exacerbations and certain cardiac arrhythmias such as torsades de pointes.
In obstetrics, magnesium sulfate is the drug of choice for seizure prophylaxis and treatment in preeclampsia and eclampsia.
It serves as neuroprotection in women at risk of preterm delivery before 32 weeks of gestation.
Typical dosing regimens for seizure prophylaxis involve a 4–6 g intravenous loading dose, followed by a maintenance infusion of 1–2 g/h.
Magnesium sulfate acts as a central nervous system depressant, vasodilator, and calcium antagonist.
Toxicity is dose-dependent and can manifest as loss of deep tendon reflexes, respiratory depression, and cardiac arrest at high serum concentrations, necessitating careful monitoring during administration.
Most commonly used tocolytic agent.
Intravenous infusions suppress recurrent torsades de pointes and ventricular ectopy in heart failure.