Spironolactone to Decrease Potassium Wasting in Hypercalciurics on Thiazides Diuretics

Idiopathic Hypercalciuria Clinical Trial

Official title:

Spironolactone to Decrease Potassium Wasting in Hypercalciuric Patients Treated With Thiazide Diuretics

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT00276289
• Other study ID #: 0509-05
• Status: Completed
• Phase: N/A
• First received: January 11, 2006
• Last updated: December 2, 2009
• Start date: January 2006
• Est. completion date: June 2006

Study information

• Verified date: December 2009
• Source: Indiana University
• Contact: n/a
• Is FDA regulated: No
• Health authority: United States: Food and Drug Administration
• Study type: Interventional

Clinical Trial Summary

Kidney stone formation due to an excess of calcium in the urine is a common problem. It is treated with thiazide diuretics. These drugs often cause excessively low blood potassium levels that in turn require large doses of potassium supplements. These supplements are often large, unpleasant and easy to forget. We are trying the addition of spironolactone to these patients' medications to see if it allows them to take a lower dose of potassium.

Description:

See rationale above

Ten patients who have had multiple kidney stones primarily due to hypercalciuria and who are currently on stable dose of thiazide or thiazide plus amiloride will be enrolled in the study. In addition, pts have to require at least 60mEq of K supplementation a day or be on 40mEq and be hypokalemic and unable to tolerate increased K supplements. We will then give them 50mg a day of spironolactone for four weeks. A complete 24-hour urine stone profile will be obtained before and after the drug is administered. After four weeks the patients' serum potassium will be rechecked, and their dose will be lowered according to a nomogram.

Primary end point is the mean change in serum K before and after spironolactone. Secondary endpoints are the change in urine calcium on and off the drug and the mean reduction in K dose on the drug.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 10
• Est. completion date: June 2006
• Accepts healthy volunteers: No
• Gender: Both
• Age group: 18 Years to 65 Years

Eligibility

Inclusion Criteria:

• Age 18-65

• History of idiopathic hypercalciuria (>200mg per 24 hours or a Ca/cr ratio of >140) felt to be the primary etiology of patient's kidney stones

• History of at least three kidney stone events

• On same dose of thiazide diuretic for at least three months

• On stable dose of K 60mEq or more a day to maintain serum K >3.5 or unable to tolerate an increase in K supplement with dose at least 40mEq a day

Exclusion Criteria:

• Use of ACE inhibitor, ACE receptor blocker or other medication known to effect serum potassium levels

• GFR <80 by MDRD equation

• Serious cardiac disease, diabetes, CKD , current or planned pregnancy or breastfeeding

• History of hypertension

Study Design

Allocation: Non-Randomized, Endpoint Classification: Efficacy Study, Intervention Model: Crossover Assignment, Masking: Open Label, Primary Purpose: Treatment

Related Conditions & MeSH terms

• Bartter Syndrome
• Hypercalciuria
• Hypokalemia
• Hypokalemia Caused by Thiazide Diuretics
• Idiopathic Hypercalciuria

Intervention

Drug:
• Spironolactone

Locations

Country	Name	City	State
United States	Indiana University Department of Medicine, Division of Nephrology	Indianapolis	Indiana

Sponsors (1)

Lead Sponsor	Collaborator
Indiana University School of Medicine

Country where clinical trial is conducted

United States, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Change in serum potassium on spironolactone versus off of it
Secondary	change in urinary calcium excretion
Secondary	mean reduction in dose of potassium supplements