RENAL + GU: POTASSIUM, IV

Question 1

POTASSIUM, IV: INDICATIONS

Answer 1

• prevention of potassium depletion in patients

- Tx of established potassium depletion and hypokalaemia

Question 2

POTASSIUM, IV: MOA

Answer 2

• The normal potassium requirement to prevent potassium depletion is about 1 mmol/kg/day in adults
• In patients unable to tolerate dietary intake, who are instead receiving their sodium and water requirement by IV infusion, potassium must also be provided intravenously
• Established potassium depletion and hypokalaemia may be caused, for example, by diarrhoea, vomiting, or secondary hyperaldosteronism. In severe cases, hypokalaemia may result in arrhythmias (which may be life-threatening), muscle weakness and (in extreme cases) paralysis. IV potassium repletion in these scenarios may be life-saving.
• 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.

Question 3

POTASSIUM, IV: ADVERSE EFFECTS

Answer 3

• Hyperkalaemia and risk of arrhythmias

- Potassium-containing solutions are irritant to veins if infused to rapidly or in a high concentration

Question 4

POTASSIUM, IV: WARNINGS

Answer 4

• Renal impairment or oliguria

Question 5

POTASSIUM, IV: INTERACTIONS

Answer 5

• potassium elevating drugs, including oral potassium supplements, aldosterone antagonists, potassium-sparing diuretics, ACE inhibitors and angiotensin-receptor blockers.

Question 6

POTASSIUM, IV: EXAMPLES

Answer 6

• POTASSIUM CHLORIDE (AS A CONSTITUENT OF IV FLUID PREPARATIONS)