Potassium Deficiency (Hypokalemia): Drug Therapy

Therapeutic targets

• Correction of hypokalemia, i.e., supplementation of potassium.
• Avoidance of cardiac arrhythmias

Therapy recommendations

• Compensation of potassium deficiency; in case of concomitant hypomagnesemia (magnesium deficiency) or magnesium in the lower normal range, also supply of magnesium:
  • Mild forms of hypokalemia (serum potassium 2.5-3.5 mmol/l): intake of potassium-rich foods (see below “Further therapy“); if necessary, additional intake of potassium-rich supplements (optimal: potassium citrate, if necessary in combination with magnesium citrate; less tolerated is potassium chloride).
  • Moderate to severe forms of hypokalemia (serum potassium < 2.5 mmol/l) with clinical symptoms: parenteral potassium chloride administration under ECG and potassium control;
    • Intake of 0.2 mmol potassium per kg per h; maximum daily dose: 3 mmol/kg bw potassium chloride; maximum dose: 20 mmol/h (10-40 mmol/h).
    • Note: Too rapid and too high a dose of potassium can cause ventricular fibrillation. Do not supply potassium in glucose solutions. This would lead to rapid intracellular (“inside the cell”) potassium uptake.If hypomagnesemia (magnesium deficiency) is present, the potassium deficit should be compensated only with simultaneous magnesium substitution.
    • Rule of thumb: 1 mmol deviation of the serum potassium level = potassium deficiency of about 100 mmol.
• See also under “Further therapy“.