Magnesium Sulfate Flashcards
1
Q
Magnesium Sulfate
Class
A
- Electrolyte
2
Q
Magnesium Sulfate
Mechanism of action
A
- Reduction of ACh release at myoneural junction causes reduced striated muscle contraction and peripheral neuromuscular transmission
- Manage eclampsia & induce uterine relaxation
- Bronchodilator after beta-agonists & anticholinergics have been administered
3
Q
Magnesium Sulfate
Indications
A
- Severe and refractory asthma
- SZ of eclampsia
- Torsades
- Hypomagnesemia
- Class IIa agent for VF/pulseless VT refractory to lidocaine
4
Q
Magnesium Sulfate
Contraindications
A
- Heart blocks
- Myocardial damage
5
Q
Magnesium Sulfate
Adverse reactions
A
- CNS depression
- Hypotension
- Circulatory collapse
- Facial flushing
- Diaphoresis
6
Q
Magnesium Sulfate
Drug interactions
A
- Enhance effects of CNS depressants
- May cause severe changes in cardiac function with cardiac glycosides
7
Q
Magnesium Sulfate
Dosage and administration (Adult)
A
- Bronchodilation: 0.5-2g IV slow push
- Eclampsia: 1-4g IV over 3 minutes; max of 30-40 g/ day
- Cardiac arrest due to hypomagnesemia or torsades: 1-2 g (2-4 mL of a 50% solution) diluted in 10 mL of D5W IV over 5-20 minutes
-
Torsades with a pulse or AMI with hypomagnesemia:
- Loading dose 1-2 g in 50-100 mL D5W over 5-60 min IV.
- Follow with 0.5-1 g/hr IV (titrate to control torsades)
8
Q
Magnesium Sulfate
Dosage and administration (Pediatric)
A
- Ped:
- Asthma & IV/IO infusion:
- 25-50 mg/kg over 10-20 min
- Max dose: 2 gm
- Push faster for torsades
9
Q
Magnesium Sulfate
Duration of action
A
-
IV
- Onset: Immediate
- Duration: 30 min
-
IM
- Onset: 3-4 hrs
- Duration: 3-4 hrs
10
Q
Magnesium Sulfate
Special consideration
A
- Preg: Cat B
- Withhold drug 2 hrs before delivery if feasible
- IV calcium chloride or calcium gluconate should be available as a magnesium antagonist if needed
- Use cautiously for pt in renal failure
