POTASSIUM

What it is

Potassium chloride 22.3% concentrated injection contains 2.23 g of potassium chloride in 10 mL. Each vial contains 30 mmol potassium ions and 30 mmol chloride ions. The product is a clear colourless sterile solution. This is a concentrated solution and may be dangerous if used undiluted.

Approved indications

— Treatment of potassium depletion in patients with hypokalaemia. — Treatment of digitalis intoxication.

Dosing overview

Potassium chloride 22.3% concentrated injection is a concentrated solution and must be diluted before use, and is administered intravenously only after dilution in a large volume parenteral fluid. The dose and rate of injection are dependent upon the individual patient's condition. The usual maximum concentration is 40 mmol/L. In patients whose serum potassium concentration is above 2.5 mmol/L, the rate of infusion should not exceed 10 mmol/hour. The total dose should not exceed 200 mmol/24 hours. If urgent treatment is required (serum potassium concentration less than 2 mmol/L with ECG changes or paralysis), potassium may be infused at a rate of 40 mmol/hour, up to a rate of 400 mmol/24-hour-period.

Key safety warnings

In patients with impaired mechanisms for excreting potassium, administration of potassium salts can produce hyperkalaemia and cardiac arrest, which is an important concern in patients given intravenous potassium. Potentially fatal hyperkalaemia can develop rapidly and be asymptomatic. In patients being given potassium, especially by intravenous administration, monitoring of serum electrolytes, the ECG and the patient's clinical status is indicated. The use of potassium salts in patients with chronic renal disease, adrenal insufficiency or any other condition which impairs potassium excretion requires particularly careful monitoring of the serum potassium concentration and appropriate dosage adjustment. Hypokalaemia should not be treated by the concomitant administration of potassium salts and potassium-sparing diuretics, since the simultaneous administration of these agents can produce severe hyperkalaemia. Symptoms of potassium intoxication include paraesthesias of the extremities, flaccid paralysis, listlessness, mental confusion, weakness and heaviness of the legs, fall in blood pressure, cardiac arrhythmias and heart block. Nausea, vomiting, diarrhoea and abdominal discomfort have been reported.

Contraindications

Potassium chloride 22.3% concentrated injection is contraindicated in renal impairment with oliguria or azotaemia, ventricular fibrillation, untreated Addison's disease, hyperadrenalism associated with adrenogenital syndrome, extensive tissue breakdown as in severe burns, acute dehydration, heat cramps, increased sensitivity to potassium administration as in adynamia episodica hereditaria or congenital paramyotonia, and hyperkalaemia of any aetiology.

Regulatory history

Potassium chloride 22.3% concentrated injection was first approved on 14 October 1991.