Treatment for Calcium Phosphate Kidney Stone Disease

The University of Texas System (UT)

Status and phase: Completed; Phase 2

Conditions: Calcium Phosphate Kidney Stones

Treatments: Dietary Supplement: Placebo; Dietary Supplement: Potassium Citrate; Dietary Supplement: Citric Acid

Study type: Interventional

Funder types: Other; NIH

Identifiers

NCT01754779

R21DK097476-01 (U.S. NIH Grant/Contract)

032012-058

Details and patient eligibility

About

The investigators will examine in two studies whether citric acid or potassium citrate can reduce calcium phosphate saturation in urine of Calcium Phosphate stone formers.

Full description

We will examine in two short-term placebo-controlled cross-over metabolic studies whether citric acid or potassium citrate can reduce calcium phosphate saturation in urine of CaP stone formers.

The first study will be conducted in hypocitraturic CaP stone formers without hypercalciuria, and will compare the effects of potassium citrate, citric acid and placebo.

The second study will be conducted in hypercalciuric CaP stone formers on a thiazide diuretic who require potassium supplementation, and will compare the effects of potassium chloride alone, potassium chloride + citric acid, and potassium citrate alone. Physicochemical assays will be applied in addition to computer-based stone risk prediction programs to assess risk of stone recurrence.

Enrollment: 13 patients

Sex: All

Ages: 21+ years old

Volunteers: No Healthy Volunteers

Inclusion and exclusion criteria

Inclusion Criteria:

Aim 1

• Hypocitraturic CaP stone formers
• urine citrate <320mg/d
• elevated pH as 24-hr urine pH above 6.40
• >21 years

Aim 2

• Hypercalciuric CaP stone formers
• 24hr urine calcium >250mg/d in women and >300mg/d in men prior to indapamide use
• high pH as >6.40 in the absence of urinary tract infection
• >21 years

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Crossover Assignment

Masking: Double Blind

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13 participants in 6 patient groups

Placebo, then Citric Acid, then Potassium Citrate

Experimental group

Description:

Participants will receive at random, First intervention (1 week), then experience a washout period (1 week) and then receive Second Intervention (1 week) followed by another washout period of 1 week to finally receive the Third Intervention (1 week)

Treatment:

Dietary Supplement: Citric Acid

Dietary Supplement: Placebo

Dietary Supplement: Potassium Citrate

Placebo, then Potassium Citrate, then Citric Acid

Experimental group

Description:

Participants will receive at random, First intervention (1 week), then experience a washout period (1 week) and then receive Second Intervention (1 week) followed by another washout period of 1 week to finally receive the Third Intervention (1 week)

Treatment:

Dietary Supplement: Citric Acid

Dietary Supplement: Placebo

Dietary Supplement: Potassium Citrate

Potassium Citrate, then Placebo, then Citric Acid

Experimental group

Description:

Participants will receive at random, First intervention (1 week), then experience a washout period (1 week) and then receive Second Intervention (1 week) followed by another washout period of 1 week to finally receive the Third Intervention (1 week)

Treatment:

Dietary Supplement: Citric Acid

Dietary Supplement: Placebo

Dietary Supplement: Potassium Citrate

Potassium Citrate, then Citric Acid, then Placebo

Experimental group

Description:

Participants will receive at random, First intervention (1 week), then experience a washout period (1 week) and then receive Second Intervention (1 week) followed by another washout period of 1 week to finally receive the Third Intervention (1 week)

Treatment:

Dietary Supplement: Citric Acid

Dietary Supplement: Placebo

Dietary Supplement: Potassium Citrate

Citric Acid, then Potassium Citrate, then Placebo

Experimental group

Description:

Participants will receive at random, First intervention (1 week), then experience a washout period (1 week) and then receive Second Intervention (1 week) followed by another washout period of 1 week to finally receive the Third Intervention (1 week)

Treatment:

Dietary Supplement: Citric Acid

Dietary Supplement: Placebo

Dietary Supplement: Potassium Citrate

Citric Acid, then Placebo, then Potassium Citrate

Experimental group

Description:

Participants will receive at random, First intervention (1 week), then experience a washout period (1 week) and then receive Second Intervention (1 week) followed by another washout period of 1 week to finally receive the Third Intervention (1 week)

Treatment:

Dietary Supplement: Citric Acid

Dietary Supplement: Placebo

Dietary Supplement: Potassium Citrate