Magnesium Sulfate

Question 1

Trade Name

Answer 1

Epsom Salt

Question 2

Class

Answer 2

Gastrointestinal agent, laxative: Anticonvulsant, smooth muscle relaxant

Question 3

Mechanism of Action

Answer 3

Important role in meurochemical transmission and muscular excitability, decreases myocardial irritability and neuromuscular irritability

Question 4

Indications

Answer 4

Torsades de pointes - drug of choice, VF/Pulsless VT, hypomagnesemia, preterm labor, pregnancy-induced hypertension, pre-eclampsia, eclampsia, refractory bronchospams

Question 5

Contraindications/precautions

Answer 5

Hypermagnesemia, use cautiously in patients with impaired renal function and pre-existing heart blocks (relative). Absolute contraindication is history of myasthenia gravis

Question 6

Averse effects

Answer 6

Hypotension (may be transient), nausea and vomiting, flushing, circulatory collapse, depressed cardiac function, heart block, systole, smooth muscle relaxant (antihypertensive effects), respiratory depression.
Signs of toxicity: decreased respirations (12 or less/min). loss of deep tendon reflexes, hypotension, extreme muscle relaxation.

Question 7

Incompatabilities/ Drug interactions

Answer 7

Concurrent digitalization increases danger of dysrhythmias

Question 8

Routes of Admin

Answer 8

IV/IO bolus and infusion

Question 9

Onset of action

Answer 9

Onset in seconds, duration of 24hrs or greater

Question 10

Adult dose

Answer 10

Pre-Eclampsia / Eclampsia - 5gm slow IVP over 20min or use 250ml bag of NS for bolus

Cardiac Arrest (if torsades de pointes) - 1-2gms IVP

Question 11

Pediatric dose

Answer 11

Cardiac Arrest (if torsades de pointes) - 25-50mg/kg IVP max 2gm

Question 12

Protocols used

Answer 12

A-10: VF/VT
A-11: VT with pulse
A-19: Pre-Eclamsia/Eclampsia
B-7: pediatric V-fib