Magnesium Sulfate Flashcards
Drug classification
Electrolyte/antidysrythmIc
Mechanism of action
SMC Ca2+ channel blocker -> inhibits calcium channel entry and the subsequent interaction between actin and myosin in smooth muscle cells-> smooth muscle relaxation and dilation of blood vessels and bronchial tree
CARDIAC Ca2+ channel blocker-> negative chronotropy, inotropy, dromotropy
Pharmacokinetics
Onset of action
Peak effects
Duration of effects
Half life
- Onset of action- immediate IV, 1 hour IM
- Peak effects- varies
- Duration of effects- 1 hour
- Half life- n/a
Indications/field use
- Severe asthma/bronchospasms
- severe refractory VF or pulseless VT with hypoMg2+, torsades de points
- eclampsia
Contraindications
3rd degree heart block, hypotension
Side effects/adverse reactions
Sweating, flushing, itching, rash. Bradycardia, hypotension, drowsiness, respiratory depression. Dysrhythmias
Dose
ADULT:
Asthma: 2g in 100cc NS IV/IO infusion over 10 minutes
VT/VF/Torsades no pulse: 2g IV/IO over 1-2 minutes
VT/Torsades with pulse: 1-2g in 50-100cc NS IV/IO over 5-60 minutes
Eclampsia- 4g in 20mL IV/IO over 5 minutes
PEDI:
Asthma- 25-50 mg/kg IV/IO infusion over 15-30 min MAX DOSE 2g
VT/Torsades no pulse- 25-50mg/kg IV/IO MAX DOSE 2g
VT/Torsades with pulse- 25-50mg/kg IV/IO over 10-20 minutes MAX DOSE 2g
Precautions
Caution with impaired renal failure
Watch for respiratory depression
Drug-drug interaction
Cardiac conduction abnormalities if given with digitalis
Infusion Sheet
Magnesium Sulfate 5g in 10cc= .5g per cc
Asthma: 2 grams in 100cc over 10 minutes
VT/VF Torsades without a pulse
2cc from a 10cc vial= 1 gram
4cc from a 10cc vial= 2 grams
8cc from a 10cc vial= 4 grams