Potassium citrate and its uses

Potassium citrate (also known as tripotassium citrate) is the potassium salt of citric acid with the molecular formula K3C6H5O7.It is a white, hygroscopic crystalline powder. Odorless, with a salty taste.It contains 38.28% by mass of potassium. In the monohydrate form, it is highly hygroscopic and deliquescent.As a food additive,potassium citrate is used to regulate acidity and is known as E number E332.In medicine,it is used to control kidney stones derived from uric acid or cystine.In 2020,it was the 297th most prescribed drug in the U.S. with over 1 million prescriptions.

Synthesis 

Potassium citrate can be synthesized by neutralizing citric acid by adding potassium bicarbonate,potassium carbonate or potassium hydroxide.The solution can then be filtered and the solvent can be evaporated until granulation.

Uses

Potassium citrate is rapidly absorbed after oral administration and excreted in the urine.Since it is an alkaline salt, it is effective in reducing painful urination and frequent urination caused by highly acidic urine.It is used for this purpose in dogs and cats,but primarily as a non-stimulant diuretic.Potassium citrate is effective in the treatment/control of gout and cardiac arrhythmias,if the patient is hypokalemic.

It is widely used to treat urolithiasis (kidney stones) and is often used by people with cystinuria.A systematic review showed a significant reduction in the incidence of stone formation RR 0.26, 95% CI 0.10 to 0.68.It is also used as an alkalizing agent in the treatment of mild urinary tract infections such as cystitis.

It is also used as a buffer in many soft drinks.Often used in aqueous solution with other potassium salts,it is a wet chemical extinguishing agent especially useful for fighting kitchen fires.Its alkaline pH value promotes saponification, isolates fuel from oxidizing air, and absorbs heat energy in endothermic dehydration reaction to lower temperature.

Administration 

Potassium citrate is usually given orally in a dilute aqueous solution because of its somewhat corrosive effect on the stomach lining and possible other minor health hazards.