Hydroxycitrate: A Novel Therapy for Calcium Phosphate Urinary Stones

The University of Texas System (UT)

Status and phase: Enrolling; Phase 4

Conditions: Calcium Phosphate Kidney Stones

Treatments: Drug: Placebo; Dietary Supplement: OHCit- standard dose; Drug: Potassium Citrate; Dietary Supplement: OHCit- low dose

Study type: Interventional

Funder types: Other

Identifiers

NCT06003348

2023-0339

Details and patient eligibility

About

This study tests whether hydroxycitrate, a molecule closely related to citrate, can reduce calcium phosphate stone recurrence.

Full description

In this double-blind, placebo-controlled, randomized, crossover study, each participant will undergo 4 phases of study, with the order randomized by a blocked randomization scheme. The 4 phases will be Placebo, Super CitriMax (hydroxycitrate) OHCit low dose, OHCit standard dose, or Potassium Citrate. Randomization will be stratified based on sex, concomitant thiazide use, and concomitant alkali use.

Each phase will be 1 week in duration, during which subjects will take assigned study medications. A minimum 1-week washout period will be imposed between phases. During the first 2 days of each phase, subjects will be instructed to adhere to a prescribed diet. On the last 5 days of each phase, subjects will be kept on a constant metabolic diet. Use of metabolic diet is essential to eliminate confounders that could occur from changes in dietary intake across phases. During the final two study days (days 6-7), two 24-hr urines will be collected for urine biochemistry and crystallization studies. Fasting blood will be obtained at the end of the last urine collection.

Study Medications: Subjects will receive three tablets twice daily during each phase. These will consist of either placebo, Potassium Citrate (KCit), or Super CitriMax (OHCit). Study tablets will be prepared by a compounding pharmacy, with placebo tablets similar in appearance and size to the active medication tablets.

Enrollment: 25 estimated patients

Sex: All

Ages: 21 to 99 years old

Volunteers: No Healthy Volunteers

Inclusion criteria

• Calcium Phosphate stone formers

Exclusion criteria

• History of recurrent urinary tract infections
• Chronic diarrhea
• Estimated Glomerular Filtration Rate (eGFR) < 45 ml/min/1.73 m2
• History of primary hyperparathyroidism
• Hypokalemia
• Hyperkalemia
• Pregnancy

Trial design

Primary purpose: Prevention

Allocation: Randomized

Interventional model: Crossover Assignment

Masking: Quadruple Blind

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25 participants in 4 patient groups, including a placebo group

Potassium Citrate (Urocit®-K)

Active Comparator group

Description:

Potassium Citrate KCit 10 mEq 2 tabs, twice daily and Placebo 1 tab, twice daily Total Daily Dose: Citrate 40 mEq/d

Treatment:

Drug: Potassium Citrate

Super CitriMax; OHCit-standard dose

Experimental group

Description:

Super CitriMax 7 mEq 3 tabs, twice daily Total Daily Dose: OHCit 42 mEq/d

Treatment:

Dietary Supplement: OHCit- standard dose

Super CitriMax; OHCit-low dose

Experimental group

Description:

Super CitriMax 7 mEq 2 tabs, twice daily And Placebo 1 tab, twice daily Total Daily Dose: OHCit 28 mEq/d

Treatment:

Dietary Supplement: OHCit- low dose

Placebo

Placebo Comparator group

Description:

Placebo 3 tablets twice daily Total Daily Dose: None

Treatment:

Drug: Placebo