Magnesium

Chemical

Inorganic sulphate & major intracellular cation

Use

Tx – Torsades de Pointes

Presentation

2.47g in 5mL

Clear colourless solution

Dose

10mmol MgSO4 (IV)

MoA

  1. Co-factor of Na/K/ATPase
  2. L-type Ca2+ channel antagonist = ↓Ca2+ flux
  3. ↑AV conduction time

ECG effects

  1. Prolongs R – R interval
  2. ↑PR interval

PD

CVS

  • Vasodilation
  • Prolongs SA & AV conduction

Resp: bronchodilation

PK

A

N/A

D

30% PPB

M

N/A

E

50% excrete din urine

Adverse Effects

  • Warmth, flushing, headache
  • Cardiac arrhythmias
  • Severe bradycardia