Magnesium Sulfate

Question 1

Generic/Trade Name

MAGNESIUM SULFATE

Answer 1

MAGNESIUM SULFATE

Question 2

MAGNESIUM SULFATE

Drug Classification:

Answer 2

Electrolyte

Antidysrhythmic

Mineral

Question 3

MAGNESIUM SULFATE

Mechanism of Action:

Answer 3

Physiologic Ca2+ channel blocker ⇒ blocks neuromuscular transmission, causes CNS depression and smooth muscle relaxation

Question 4

MAGNESIUM SULFATE

Pharmacokinetics

Answer 4

• Onset of Action = Immediate IV, 1 hour IM
• Peak Effects = Varies
• Duration of Effect = 1 hour
• Half-Life = N/A

Question 5

MAGNESIUM SULFATE

Indications & Contraindications

Answer 5

Indications/Field Use:

• Severe Asthma / Bronchospasm
• Severe refractory VF or pulseless VT w/ hypoMg2+, and Torsades de Pointes
• Post-MI prophylaxis of dysrhythmias
• Eclampsia, Pre-Term Labor

Contraindications:

• Pt. w/ 3° heart block
• shock
• severe/persistent hypertension
• impaired renal function
• hypocalcemia

Question 6

MAGNESIUM SULFATE

Side Effects/Adverse Reactions

Answer 6

Flushing, sweating

bradycardia, dysrhythmias, hypotension, hypothermia

decreased deep tendon reflexes, drowsiness,
respiratory depression

itching, rash

Question 7

MAGNESIUM SULFATE

Adult & Pedi Dose:

Answer 7

• *Asthma (ADULT):** 2g in 100cc NS IV, IO infusion over 10 minutes
• *VT,VF, Torsades-no pulse (ADULT):** 2g IVP (IO) over 1-2 minutes
• *VT/Torsades +pulse (ADULT):** 1-2g in 50-100cc NS, slow IVP (IO) over 5-60 minutes
• *Eclampsia (ADULT):** 2-4g slow IV, IO over 25 min, IM if IV access unavailable
• *Asthma (PEDI):** 25-50mg/kg slow IV, IO infusion over 15-30min, max dose 2g
• *VT-no pulse (PEDI):** 25-50mg/kg IVP (IO), max dose 2g
• *VT+pulse (PEDI):** 25-50mg/kg IV, IO over 10-20 minutes, max dose 2g

Question 8

MAGNESIUM SULFATE

Precautions:

Answer 8

• Monitor vitals
• Watch for respiratory depression
• Have CaCl2 available if OD

Question 9

MAGNESIUM SULFATE

Drug-Drug Interactions:

Answer 9

Cardiac conduction abnormalities if given with digitalis