Magnesium%2525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252520sulphate

# Magnesium Sulphate ## Overview Magnesium sulphate is an essential mineral that plays a role in numerous biochemical reactions in the body, including neuromuscular transmission, cardiac conduction, and smooth muscle function. ## Primary Indications * Treatment of hypomagnesemia. * Prevention and treatment of seizures in severe pre-eclampsia and eclampsia. * Management of torsades de pointes. * Treatment of status asthmaticus. ## Adult Dosing * **Hypomagnesemia:** * Intravenous: 2-4 g (approximately 16-32 mEq) may be infused over 5-60 minutes, followed by an infusion of 1 g/hour as needed. Alternatively, 1 g (8 mEq) may be added to 1 L of IV fluid and infused over 12-24 hours. * Intramuscular: 1-2 g (8-16 mEq) every 4-6 hours for 4 doses, as needed. * **Pre-eclampsia/Eclampsia:** Loading dose: 4-6 g (32-48 mEq) IV over 15-20 minutes. Maintenance dose: 1-2 g/hour IV infusion. *Dosing may vary based on local protocol and patient response.* * **Torsades de Pointes:** 1-2 g (8-16 mEq) IV in 100 mL D5W or NS over 5-10 minutes. May repeat every 5-15 minutes. Follow with infusion of 0.5-1 g/hour. * **Status Asthmaticus:** 25-40 mg/kg (max 2 g) IV over 15 minutes. ## Pediatric Dosing * **Hypomagnesemia:** * Intravenous: 20-50 mg/kg/dose (0.1-0.25 mEq/kg/dose) every 4-6 hours, not to exceed 1 g (8 mEq) per dose. * Intramuscular: 20-50 mg/kg/dose (0.1-0.25 mEq/kg/dose) every 4-6 hours. * **Eclampsia:** Loading dose: 40 mg/kg (max 2 g) IV over 10-20 minutes. Maintenance dose: 10-20 mg/kg/hour IV infusion. *Dosing may vary based on local protocol.* * **Status Asthmaticus:** 25-40 mg/kg (max 2 g) IV over 15 minutes. ## Dose Adjustments Reduce dose in patients with impaired renal function. Dialysis may remove magnesium. ## Contraindications * Hypermagnesemia. * Heart block or myocardial damage. * Use with caution in patients with myasthenia gravis. ## Adverse Effects * **Common:** Flushing, sweating, hypotension, somnolence, decreased deep tendon reflexes. * **Serious:** Respiratory depression, cardiac arrest, hypermagnesemia (nausea, vomiting, muscle weakness, absent reflexes, hypotension, bradycardia, cardiac arrhythmias). ## Key Drug Interactions * **Neuromuscular Blockers:** Magnesium can potentiate neuromuscular blockade. * **Calcium Channel Blockers:** Increased risk of hypotension and neuromuscular blockade. * **Digoxin:** Increased risk of digoxin toxicity with hypermagnesemia. ## Monitoring * Serum magnesium levels (target 1.7-2.6 mEq/L for hypomagnesemia, higher targets for eclampsia). * Renal function (BUN, creatinine). * Deep tendon reflexes. * Respiratory rate and effort. * Blood pressure. * Urine output. * Electrocardiogram (ECG) if cardiac issues suspected. ## Clinical Pearls * Magnesium sulphate is a CNS depressant and a vasodilator. * Hypocalcemia can occur secondary to magnesium therapy; monitor calcium levels if necessary. * IV administration should be slow to avoid hypotension. * The antidote for magnesium toxicity is intravenous calcium (e.g., calcium gluconate). *** **Disclaimer:** This information is intended for healthcare professionals and is not a substitute for clinical judgment. Always consult the most current prescribing information and institutional protocols before administering any medication.