Potassium chloride

Also known as

• Intravenous potassium

 

Medicinal forms

• Not available as a ‘stand-alone’ solution on general wards.
• Component of Compound sodium lactate (5 mmol/L).
• 20 or 40 mmol/L added to Sodium chloride or Glucose. 

 

Common indications

• For prevention of potassium depletion in patients unable to take adequate amounts orally.
• For treatment of established potassium depletion and hypokalaemia that is 
• severe (<2.5 mmol/L)
• symptomatic
• causing arrhythmias

 

Mechanisms of action

• The normal potassium requirement to prevent potassium depletion is about 1 mmol/kg/day in adults.
• For the best effect, IV potassium is given with sodium chloride rather than glucose. This is because the negatively charged chloride ions promote retention of K+ in the serum for longer, whereas glucose may promote insulin release with resultant stimulation of Na+/K+-ATPase, shifting potassium into cells.

 

Important adverse effects

• The major risk of IV potassium infusion is overcorrection leading to hyperkalaemia and a resultant risk of arrhythmias. 
• Potassium-containing solutions are irritant to veins if infused rapidly or in too high concentration.
• For this reason, the infusion rate in a peripheral vein should generally not exceed 20 mmol/hr. 

Warnings

• It is unnecessary and potentially dangerous to prescribe potassium for the prevention of potassium depletion in patients with renal impairment or oliguria, as they have minimal potassium losses and are very susceptible to hyperkalaemia. 
• In the unusual situation in which potassium depletion and hypokalaemia develop in these settings, extreme caution should be exercised in their treatment.