Magnesium%252525252525252525252525252525252520sulphate

# Magnesium Sulphate ## Overview Magnesium sulphate is a parenteral mineral supplement used for electrolyte replacement, seizure prophylaxis, and as a bronchodilator in acute severe asthma. It acts as a calcium antagonist and CNS depressant. ## Primary Indications * Hypomagnesemia * Eclampsia and pre-eclampsia (seizure prophylaxis) * Torsades de pointes (ACLS protocol) * Adjunctive therapy in acute severe asthma (refractory to initial treatment) ## Adult Dosing * **Hypomagnesemia:** 1–2 g IV/IM over 15–60 minutes. Severe cases may require 4–8 g over 12–24 hours. * **Torsades de Pointes:** 1–2 g IV/IO bolus over 5–20 minutes. * **Eclampsia (Pritchard/Zuspan Regimen):** 4–6 g IV loading dose over 15–20 minutes, followed by 1–2 g/hr continuous infusion. * **Acute Asthma:** 2 g IV bolus over 15–20 minutes. ## Pediatric Dosing * **Hypomagnesemia:** 25–50 mg/kg/dose IV/IM every 6 hours for 3–4 doses. Max: 2 g/dose. * **Acute Asthma:** 25–50 mg/kg IV once (max 2 g) over 20 minutes. * *Note: Always verify dosing against local institutional weight-based protocols.* ## Dose Adjustments * **Renal Impairment:** Reduce dose in patients with renal insufficiency (CrCl <30 mL/min). Monitor levels frequently to avoid toxicity; avoid or exercise extreme caution in severe renal impairment. ## Contraindications * Heart block (unless pacemaker present) * Myocardial damage * Severe renal impairment (CrCl <20 mL/min) * Hypersensitivity to magnesium products ## Adverse Effects * **Common:** Flushing, diaphoresis, hypotension, injection site pain. * **Serious:** Magnesium toxicity (loss of deep tendon reflexes, bradycardia, respiratory depression, cardiac arrest). ## Key Drug Interactions * **Neuromuscular Blockers:** May enhance/prolong neuromuscular blockade. * **Aminoglycosides/Calcium Channel Blockers:** May potentiate neuromuscular blockade or respiratory depression. * **Digoxin:** Potential for increased susceptibility to digitalis toxicity; monitor closely. ## Monitoring * **Serum Magnesium levels:** Check every 6–12 hours initially. * **Toxicity signs:** Before each dose, confirm: 1. Presence of patellar reflex. 2. Respiratory rate >12–16 breaths/min. 3. Adequate urine output (>30 mL/hr). * **Calcium Gluconate:** Keep 10% calcium gluconate at the bedside at all times to reverse respiratory depression/toxicity. ## Clinical Pearls * **Administration:** Rapid IV bolus can cause hypotension or asystole; always infuse over the recommended timeframe. * **Antidote:** If magnesium toxicity occurs, discontinue infusion immediately and administer 1 g IV of calcium gluconate (or calcium chloride) over 5–10 minutes. * **Routes:** IM administration is painful and generally reserved for patients without IV access. *** *Disclaimer: This information is for educational purposes and does not substitute for clinical judgment. Always verify current prescribing information, institutional guidelines, and drug compatibility charts before administration.*