Potassium chloride (medical use)

Potassium chloride is used as a medication to treat and prevent low blood potassium. Low blood potassium may occur due to vomiting, diarrhea, or certain medications. The concentrated version should be diluted before use. It is given by slow injection into a vein or by mouth.

Side effects may include heart problems if given too quickly by injection into a vein. By mouth it can result in abdominal pain, peptic ulcer disease, or gastrointestinal bleeding. Greater care is recommended in those with kidney problems. As long as high blood potassium does not occur, use in pregnancy or breastfeeding is believed to be safe for the baby. Generally, the strength of the formulation for injection into a vein should not be greater than 40 mmol/l (3gm/l).

Potassium chloride came into large scale commercial use as a fertilizer in 1861 and has been used medically since the 1950s. It is on the World Health Organization's List of Essential Medicines, the most effective and safe medicines needed in a health system. Potassium chloride is available as a generic medication. The wholesale cost in the developing world is about 0.44 USD per 10 ml of 10% solution. In the United Kingdom 10 ml of 15% solution costs the NHS about 0.48 pounds.

Potassium chloride is used in the treatment of hypokalemia as an electrolyte replenisher. With a molecular weight of approximately 75 and a valence of 1, the use of KCl for electrolytes makes 75 mg the equivalent of 1 mEq.