Citrate salts are alkalinisers. They are commonly used in situations where long-term maintenance of an alkaline urine is necessary and in the management of chronic metabolic acidosis. Citric acid is also used in effervescing mixtures and as a synergist to improve the efficacy of antioxidants. It may also be used in preparations that are used in the treatment of dry mouth and to dissolve renal calculi and prevent encrustation of urinary catheters.