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Drug Reference

potassium chloride

electrolyte· Brands: Kay-Cee-L, Slow-K, Sando-K, Klor-Con, KaochlorIVPO

Mechanism of action
Potassium is the principal intracellular cation. It is essential for maintaining cellular resting membrane potential, nerve impulse conduction, muscle contraction (including cardiac muscle), and normal acid-base balance. Potassium chloride supplementation replaces deficits to restore normal physiological functions.
Pharmacokinetics
Potassium chloride is rapidly and nearly completely absorbed from the gastrointestinal tract, primarily in the small intestine. It is distributed widely, with the majority of potassium located intracellularly. Excretion is mainly renal, with a small amount lost via faeces and sweat. The onset of action depends on the route of administration.
Indications & dosing

Hypokalemia (treatment)

For mild to moderate hypokalemia. Monitor serum potassium.

  • adult · PO: 20–40 mmol divided daily · For mild to moderate hypokalemia. Monitor serum potassium.

Hypokalemia prevention in patients receiving diuretics

Adjust based on potassium levels.

  • adult · PO: 10–20 mmol once daily · Adjust based on potassium levels.

Severe hypokalemia or inability to take oral

Must be given diluted in infusion fluid, with continuous cardiac monitoring. Maximum rate 10 mmol/h peripherally (20 mmol/h via a central line). May repeat if needed.

  • adult · IV: 20–40 mmol over at least 1-2 hours · Must be given diluted in infusion fluid, with continuous cardiac monitoring. Maximum rate 10 mmol/h peripherally or 20 mmol/h via a central line with continuous ECG monitoring. May repeat if needed.
Contraindications & precautions
  • Hyperkalaemia · Avoid in patients with serum potassium >5.0 mmol/L or severe hyperkalaemia.
  • Severe renal impairment · Risk of accumulation; monitor potassium and renal function closely.
  • Addison's disease · Impaired potassium excretion; monitor closely.
  • Concurrent use of potassium-sparing diuretics · Risk of life-threatening hyperkalaemia; avoid or monitor closely.
  • Monitor serum potassium and renal function before and during therapy.
  • Use with caution in renal impairment, cardiac disease, or acidosis.
  • Avoid rapid IV infusion; ensure adequate dilution and use an infusion pump.
  • Concomitant use of ACE inhibitors, angiotensin receptor blockers, or potassium-sparing diuretics increases hyperkalaemia risk; monitor closely.
  • Ensure adequate urine output to prevent accumulation.
Adverse effects
  • Hyperkalaemiaserious
  • Nausea
  • Vomiting
  • Abdominal pain
  • Diarrhoea
  • Phlebitis at IV site
  • Cardiac arrhythmiasserious
  • Paraesthesia
Interactions
  • ramiprilmajorAvoid routine co-prescription unless there is clear hypokalaemia and careful monitoring is possible. If used together, monitor serum potassium at baseline, within 5 to 7 days after starting or changing doses, and regularly thereafter, especially during intercurrent illness. Adjust the potassium chloride dose or discontinue if hyperkalaemia occurs. Check renal function periodically.
  • lisinoprilmajorAvoid routine co-prescription unless there is documented hypokalaemia and the patient is closely monitored. If combined, measure serum potassium before initiation, within 1 week, and regularly thereafter. Adjust or stop potassium supplementation as needed. Monitor renal function and for signs of hyperkalaemia. Consider alternatives to potassium supplementation, such as dietary changes or potassium-sparing diuretics, with caution.
  • spironolactonecontraindicatedCo-prescription is contraindicated. If the combination is considered essential, it must be used only under specialist supervision with frequent monitoring of serum potassium, electrolytes, and renal function. Stop the potassium supplement and seek immediate medical attention if hyperkalaemia develops. Consider alternative potassium-sparing strategies or non-potassium-sparing diuretics.
Renal & hepatic adjustment
  • eGFR 60+: No adjustment required.
  • eGFR 30–59: Use with caution. Monitor serum potassium closely; reduce initial dose if hypokalaemia is present.
  • eGFR 0–29: Avoid unless hypokalaemia is documented. Use lowest effective dose and monitor potassium levels frequently. (avoid)
Monitoring, pregnancy & toxicity
  • Serum potassium · Baseline, then as directed. More frequent in renal impairment or with high doses.
  • Renal function (serum creatinine, eGFR) · Baseline and periodically during treatment.
  • ECG · In patients at risk of hyperkalaemia or with cardiac disease.
  • Pregnancy: Potassium chloride is safe for use in pregnancy when indicated for hypokalaemia, at appropriate doses. Use only if clearly needed.
  • Toxicity: Hyperkalaemia: paraesthesia, muscle weakness, bradycardia, peaked T waves on ECG, and arrhythmias. · Stop the infusion; give IV calcium gluconate (10% 10 ml over 2-5 min), insulin with glucose, nebulised salbutamol, and sodium bicarbonate if acidotic. Consider oral potassium binders or haemodialysis in severe or refractory cases.
Clinical notes
Used for the treatment and prevention of hypokalaemia, particularly in patients on diuretics or with gastrointestinal losses. Must be used with caution in renal impairment and conditions predisposing to hyperkalaemia. IV administration requires dilution and slow infusion to avoid cardiac arrhythmias. Monitor serum potassium and renal function regularly. Oral formulations may cause gastrointestinal irritation. Doses should be adjusted based on individual requirements and serum potassium levels.

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BNF; local formulary