Eclampsia Severe pre-eclampsia or eclampsia The total initial dose is 10 to 14 g of magnesium sulfate. To initiate therapy, 4 g of Magnesium Sulfate in 5% Dextrose Injection, may be administered intravenously. The rate of I.V. infusion should generally not exceed 150 mg/minute, or 7.5 mL of a 2% concentration (or its equivalent) per minute, except in severe eclampsia with seizures. Simultaneously, 4 to 5 g (32.5 to 40.6 mEq) of magnesium sulfate may be administered intramuscularly into each buttock using undiluted 50% Magnesium Sulfate Injection. After the initial I.V. dose, some clinicians administer 1-2 g/hour by constant I.V....