Magnesium sulfate

Question 1

Supplied

Answer 1

(50%) 1 gram / 2 ml (2 ml vial)

Question 2

Adult Dose

Answer 2

Eclampsia: 5 g bolus IV over 15 min (in 250 ml NS), followed by a 2 g/hr infusion.
Hypomagnesium: 2 g bolus IV over 15 min (in 250 ml NS).
Tosades de pointes: With out a pulse: 2 g over 5 min.
With a pulse: Load with 2 g in 250 ml of NS over 15 min, then infuse at 1 g/hr.

Question 3

Max adult dose

Answer 3

Max infusion rate is 150 mg/min, except in eclampsia.

Question 4

Pediatric dose

Answer 4

Neonates: 25 mg/kg IV over 15 minutes.

Question 5

Max pediatric dose

Answer 5

Max single dose 2000 mg (2 g).

Question 6

Action

Answer 6

unknown, may decrease myocardial cell excitability, modulates sodium and potassium channels.

Question 7

Indication

Answer 7

Torsades, hypomagnesemia, eclampsia.

Question 8

Contraindications

Answer 8

Heart block

Question 9

Considerations

Answer 9

Smaller dose may be needed in patients with renal insufficiency. Dilute large amounts whenever possible in NS.

Question 10

Side Effects

Answer 10

CNS: CNS depression, muscular hyporeflexia
CV: Heart block, hypotension, vasodilation
Resp: Respiratory tract paralysis

Question 11

Class

Answer 11

Magnesium replacement