Magnesium Sulfate (MgSO4)

Question 1

Classes

Answer 1

Electrolyte
CNS depressant
Anticonvulsant

Question 2

Actions

Answer 2

For treatment or prophylaxis of seizures due to toxemia of pregnancy by decreasing neuronal excitability (anticonvulsant)
Reduces the incidence of postinfarction ventricular arrhythmias by increasing membrane stability and decreasing ventricular excitability
May result in relaxation of bronchial and vascular smooth muscle which is probably secondary to calcium blockade

Question 3

Indications

Answer 3

Refactory VF/VT
Torsades de pointes
Refractory seizures related to hypomagnesemia especially in alcoholics
Eclampsia
Hyper-reflexia of toxemia of pregnancy (pre-eclampsia)
Cardiac arrhythmias due to dig toxicity
Controversial: refractory bronchospasm not responsive to beta agonist, steroids, aminophylline

Question 4

Contraindications

Answer 4

Heart block

Controversy in acute MI patient

Question 5

Side Effects

Answer 5

From too rapid IV administration: Flushing, hypotension, sweating, mild bradycardia. Hypermagnesemia may produce depressed reflexes (patella), flaccid paralysis, circulatory collapse, respiratory depression or paralysis, and diarrhea.