This phase 2 trial aims to assess the effects of citric acid and potassium citrate (both food supplements) on kidney stone formation. The main outcome to be investigated is the change in calcium phosphate (a mineral involved in kidney stone formation) present in the urine. The trial is recruiting in Dallas (Texas), USA.
Kidney stones are small mineral deposits that can form in or near the kidneys. Individuals with a lot of calcium in their urine (also known as hypercalciuria) are at increased risk of kidney stones. Citric acid is a type of supplement that may have stone prevention benefits. Citrate, used in calcium citrate supplements and in some medications (such as potassium citrate), is closely related to citric acid and may have similar benefits.
This study will examine the protective effects of citric acid and potassium citrate in kidney stone patients with and without hypercalciuria. The levels of calcium phosphate (a mineral involved in kidney stone formation) in the urine will be measured before and after treatment.
Who are they looking for?
This study will recruit about 50 patients with a history of kidney stones aged over 21 years. Patients without hypercalciuria must have citrate levels of less than 320 mg/d in their urine and high pH levels. Patients with hypercalciuria must have high pH levels as well as citrate levels over 250 mg/d in woman and over 300 mg/d in men prior to indapamide use ([Lozol] a diuretic).
How will it work
Participants without hypercalciuria will be randomly assigned to receive either potassium citrate, citric acid, or placebo (control drug with no active effect). Participants with hypercalciuria will be randomly assigned to receive either potassium chloride alone, potassium chloride with citric acid, or potassium citrate alone, all in combination with ongoing diuretic use. The levels of calcium phosphate (a mineral involved in kidney stone formation) in the urine will be measured before and 2 weeks after treatment.