Magnesium Sulfate

Question 1

Magnesium Class

Answer 1

Electrolyte / Antidysrhythmic

Question 2

Magnesium Mech SMC (1/2)

Answer 2

Ca2+ channel blocker –> inhibits calcium entry and the subsequent interaction between actin and myosin in smooth muscle cells –> smooth muscle relaxation and dilation of blood vessels and bronchial tree.

Question 3

Magnesium Mech Cardiac (2/2)

Answer 3

Ca2+ channel blocker –> negative chronotropy, inotropy, dromotropy.

Question 4

Magnesium Onset

Answer 4

Immediate IV, 1 hour IM

Question 5

Magnesium Peak

Answer 5

Varies

Question 6

Magnesium Duration

Answer 6

1 hour

Question 7

Magnesium Half-Life

Answer 7

N/A

Question 8

Magnesium Indications (3)

Answer 8

Severe asthma / bronchospasm; severe refractory VF or pulseless VT with hypomagnesemia, Torsades de Pointes; Eclampsia.

Question 9

Magnesium Contraindications (2)

Answer 9

3rd degree heart block, hypotension.

Question 10

Magnesium Side Effects

Answer 10

Flushing, sweating, bradycardia, drowsiness, respiratory depression, dysrhythmias, hypotension, itching, rash.

Question 11

Magnesium Dose Adult

Answer 11

Asthma 2g in 100cc IV/IO over 10 mins, VF/VT/Tor (no pulse) – 2g over 1-2 minutes, (with pulse) – 1-2 grams in 50-100cc over 5-60 mins, eclampsia – 4g in 20 ml over 5 min.

Question 12

Magnesium Dose Child

Answer 12

Asthma: 25-50 mg/kg IV/IO over 15-30 mins (max: 2g), VT/VF/Tor (pulse or no pulse) 25-50 mg/kg IV/IO over 10-20 mins (max 2g)

Question 13

Magnesium Precautions (2)

Answer 13

Caution with impaired renal function; watch for respiratory depression.

Question 14

Magnesium Drug-Drug interactions

Answer 14

Cardiac conduction abnormalities if given with digitalis.