Cardiovascular DiseasesPhase 3NCT00241839
Uric Acid and Hypertension in African Americans
A Phase 3 study testing Allopurinol, Chlorthalidone and Potassium chloride in people with Cardiovascular Diseases and Heart Diseases, run by University of Florida at 1 site in United States.
Trial summary
This study will test the hypothesis that the administration of a xanthine oxidase inhibitor (allopurinol) will prevent thiazide-induced hyperuricemia, which will result in better blood pressure (BP) control in African Americans. Read more about this study
- Who is it for?
- Ages 18 to 65 years
- Conditions the study is for
- Cardiovascular Diseases, Heart Diseases, Hypertension
- What is being tested?
- Allopurinol, Chlorthalidone and Potassium chloride
- Type of treatment
- Pill or oral medicine
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 150 participants
- Where
- 1 siteUnited States
- Study dates
- Aug 2005to May 2011
- Phase
- Phase 3
- Are there results?
- Yes, posted in the registrySummary in the doctors' view
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 65 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- African American (including black individuals born in the Caribbean, Africa, Canada, etc.)
- Are either untreated with any antihypertensive agent, with an average sitting clinic BP of between 140/90 and 159/99 mm Hg OR subjects with hypertension controlled (i.e. BP less than 140/90) or no higher than stage 1 hypertension (i.e., less than 160/100) on a single antihypertensive agent or two antihypertensive agents (individuals on fixed dose ARB-diuretic or ACEI-diuretic combinations will also be considered as being on monotherapy for purposes of the study. Individuals on beta blockade or calcium channel blockade for coronary artery disease and/or arrhythmia will not be eligible for the study)
- Random spot urine protein/creatinine ratio of less than 0.5 (approximates a 24-hour urinary protein excretion of 500 mg/day)
- Calculated MDRD GFR of greater than or equal to 60 ml/min/1.73/m^2
- No allopurinol or probenecid intake for at least one month prior to study entry
- Willing and able to cooperate with study procedures
- Willing to travel to the GCRC at Shands Hospital for overnight inpatient stays on two separate occasions
Who cannot join
- History of malignant or accelerated hypertension
- Confirmed total white cell count of less than 2,500/mm^3, anemia, or thrombocytopenia
- Known history of liver disease
- Known secondary cause of hypertension
- Known presence of diabetes or fasting blood glucose greater than or equal to 126 mg/dL
- History of heart failure, acute myocardial infarction, or stroke or on a β-blocker or calcium channel blocker for cardiovascular indications other than for lowering blood pressure
Show all 15Show fewer
- Abnormal EKG requiring medical intervention
- History of clinical or renal biopsy or evidence of renal parenchymal disease
- Acute gout attack within 2 weeks of study entry
- History of drug abuse in the last 2 years, including narcotics, cocaine, or alcohol (greater than 21 drinks/week)
- Arm circumference of greater than 52 cm, which precludes measurement with a 'thigh' BP cuff
- History of a reaction to allopurinol or chlorthalidone
- Pregnant or planning to become pregnant during the study, or breastfeeding
- History of noncompliance, are unable to comply with the study requirements, or who are currently participating in another study
- Not fasting prior to obtaining screening laboratory data. If a participant has clearly not fasted, we will exclude those individuals with casual blood glucose levels of greater than or equal to 200 mg/dL. In the event that a fasting blood sugar exceeds 126 mg/dL, it will be reconfirmed on a blood glucose measurement obtained on a subsequent day, per American Diabetes Association criteria
Trial locations and contacts
1 site in 1 country.
About this study
This study will test the hypothesis that the administration of a xanthine oxidase inhibitor (allopurinol) will prevent thiazide-induced hyperuricemia, which will result in better blood pressure (BP) control in African Americans.
Read the detailed description
Thiazide diuretics when used in the treatment of hypertension are associated with many metabolic side effects, including hyperuricemia, gout, insulin resistance, and hyperlipidemia. Each of these conditions is already highly prevalent in African Americans. Our hypothesis is that thiazide-induced hyperuricemia decreases the efficacy of thiazides in controlling BP, leads to endothelial dysfunction, and increases the incidence of insulin resistance and impaired glucose tolerance. This hypothesis will be tested in a randomized, double-blind, placebo-controlled clinical trial of 8-10 weeks duration in which a total of 100 African American patients with hypertension will be enrolled, randomized, and treated as follows:
- Subjects with untreated stage I hypertension will receive chlorthalidone (25 mg/day) and potassium chloride (40 mEq/day) for 4 weeks. Serum potassium levels will be obtained after four weeks on chlorthalidone. If the level is below 3.5 mEg/L, a bolus of 40 mEq potassium 2 to 3 times daily will be given for 2 to 3 days, or as clinically indicated. A maintenance dose of 50 mEq will be initiated. After at least 7 days, they will then be randomized to add-on allopurinol (300 mg/day) or placebo. Treatment will continue for 8-10 weeks with the chlorthalidone, potassium chloride, and allopurinol/placebo regimen.
- Subjects with hypertension controlled (i.e. BP <140/90) or no higher than stage 1 hypertension (i.e., <160/100) on a single antihypertensive agent or two antihypertensive agents will be switched from their prior antihypertensive agent to chlorthalidone 25 mg/day, and potassium chloride (40mEq/day) for 4 weeks. Serum potassium levels will be obtained after four weeks on chlorthalidone. If the level is below 3.5 mEg/L, a bolus of 40 mEq potassium 2 to 3 times daily will be given for 2 to 3 days, or as clinically indicated. A maintenance dose of 50 mEq will be initiated. After at least 7 days, they will then be randomized to add-on allopurinol (300 mg/day) or placebo. Treatment will continue for 8-10 weeks with the chlorthalidone, potassium chloride, and allopurinol/placebo regimen.
The allopurinol (or placebo) dose will be adjusted to achieve serum uric acid levels between 4 and 5.5 mg/dL after 2 weeks on drug. All subjects will receive a low-sodium diet. The primary endpoint is reduction in systolic BP. Secondary endpoints measure endothelial function, ambulatory blood pressure, body composition, systemic inflammation, metabolic parameters, oxidant stress, and renal hemodynamics.
- Conditions
- Cardiovascular Diseases, Heart Diseases, Hypertension
- Being tested
- Allopurinol, Placebo, Chlorthalidone, Potassium chloride
- Medical subject headings
- Cardiovascular Diseases, Heart Diseases, Hypertension
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
AllopurinolDrug
Also called Zyloprim
Allopurinol (300 mg capsule) was given for 8-10 weeks compared to placebo group after initial baseline testing. After two weeks on the Allopurinol, a serum uric acid level was obtained. If the uric acid level was greater than 5.5, the Allopurinol dosage was increased to 600mg (two 300 mg capsules)for the duration of the trial, 6-8 weeks.
PlaceboDrug
Also called sugar pill
Placebo capsule (matched in appearance for Allopurinol and labeled 300mg) was given for 8-10 weeks compared to the Allopurinol group after initial baseline testing. After two weeks on the placebo, a serum uric acid level was obtained. If the uric acid level was greater than 5.5, the placebo dosage was increased to 600mg (two 300 mg capsules)for the duration of the study, 6-8 weeks.
ChlorthalidoneDrug
Chlorthalidone 25 mg was given daily for 5 weeks before baseline visit for testing and continued through out the study.
Potassium chlorideDrug
Potassium Chloride 40-50meq was given daily for 5 weeks before baseline visit for testing and continued through out the study.
| Study group | Role | What they receive |
|---|---|---|
| A | Active comparator | Chlorthalidone 25 mg and Potassium Chloride 40-50meq were given daily for 5 weeks before baseline visit for testing. After baseline testing was completed, Allopurinol 300mg daily was added for 8-10 weeks at which time testing was repeated. Receives: Drug: Allopurinol; Drug: Chlorthalidone; Drug: Potassium chloride |
| B | Placebo comparator | Chlorthalidone 25 mg and Potassium Chloride 40-50meq were given daily for 5 weeks before baseline visit for testing. After baseline testing was completed, a Placebo,matched in appearance to Allopurinol, was added daily for 8-10 weeks, at which time testing was repeated. Receives: Drug: Placebo; Drug: Chlorthalidone; Drug: Potassium chloride |
What is being measured
The primary outcome is the main question the study is designed to answer.
Change in Diastolic Blood Pressure by Cuff 8-10 Weeks Minus Baseline
The Diastolic BP was taken at Baseline and after 8-10 weeks of treatment or placebo while on chlorthalidone and potassium chloride. The blood pressure was measured according to "Shared Care" protocol: 15 minutes of quiet, undisturbed rest with three BP measurements obtained subsequently at 5 minute intervals.
The mean of the second and third reading was the value used for analysis for both the Baseline measurement and the measurement after 8 - 10 weeks of treatment. The dependent variable is baseline value minus ending value.
Measures are in millimeters of mercury (mm hg)
Measured: Measured at 8-10 weeks on allopurinol / placebo
Change in Systolic Blood Pressure by Cuff After 8-10 Weeks Minus Baseline
The systolic BP was taken at Baseline and after 8-10 weeks of treatment on placebo, while on chlorthalidone and potassium chloride. The blood pressure was measured according to "Shared Care" protocol: 15 minutes of quiet, undisturbed rest with three BP measurements obtained subsequently at 5 minute intervals.
The mean of the second and third reading was the value used for analysis for both the Baseline measurement and the measurement after 8 - 10 weeks of treatment. The dependent variable is baseline value minus ending value.
Measures are in millimeters of mercury (mm hg)
Measured: Measured at 8-10 weeks on allopurinol or placebo
Secondary outcomes (2)
Change in Overall Mean BP From Those Obtained by 24 Hour Ambulatory Blood Pressure Measurements (ABPM) 8-10 Weeks Minus Baseline.
Subjects had 24 hr blood pressure monitoring (ABPM) at baseline and treatment end. The readings were averaged and the changes from baseline to treatment end were compared.
Measured: Baseline and end of treatment (8-10 weeks on allopurinol / placebo)
Change in Uric Acid (UA) Levels: Baseline Less End of Treatment
Subjects on allopurinol are expected to lower their uric acid levels relative to placebo.
Measured: Baseline UA levels compared to end of treatment levels (8-10 weeks on allopurinol / placebo)
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted19 Oct 2005 (estimated)
- Study startAug 2005
- Primary completionMay 2011
- Study completionMay 2011
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Posted resultsParticipant flow, outcome measures and adverse events reported by the sponsor.
- Publications (8)Papers the sponsor has linked to this study.
- Other trials for Cardiovascular DiseasesStudies of the same condition, open and under way.
- More trials run by University of FloridaThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 3
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Double blind
- Who is masked
- Participant, Investigator
- Enrolment
- 150 participants (actual)
Sponsor and investigators
- Lead sponsor
- University of Florida
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
- Investigators
- Mark S. Segal, MD, PhD, Principal investigator, University of Florida
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT00241839
- Sponsor's protocol ID
- 332
- Other IDs
- R01HL079352
- Status last verified
- Jul 2013
- First submitted
- 17 Oct 2005
- Last updated
- 26 Jul 2013
- Results posted
- Yes, on ClinicalTrials.gov
- Data monitoring committee
- Yes
Publications
Johnson RJ, Segal MS, Sautin Y, Nakagawa T, Feig DI, Kang DH, Gersch MS, Benner S, Sanchez-Lozada LG. Potential role of sugar (fructose) in the epidemic of hypertension, obesity and the metabolic syndrome, diabetes, kidney disease, and cardiovascular disease. Am J Clin Nutr. 2007 Oct;86(4):899-906. doi: 10.1093/ajcn/86.4.899.
PubMed 17921363Nakagawa T, Johnson RJ. Hypertension: Is there a dark side to thiazide therapy for hypertension? Nat Rev Nephrol. 2010 Oct;6(10):564-6. doi: 10.1038/nrneph.2010.114. No abstract available.
PubMed 20871636Nakagawa T, Kang DH, Feig D, Sanchez-Lozada LG, Srinivas TR, Sautin Y, Ejaz AA, Segal M, Johnson RJ. Unearthing uric acid: an ancient factor with recently found significance in renal and cardiovascular disease. Kidney Int. 2006 May;69(10):1722-5. doi: 10.1038/sj.ki.5000391.
PubMed 16598194Reungjui S, Hu H, Mu W, Roncal CA, Croker BP, Patel JM, Nakagawa T, Srinivas T, Byer K, Simoni J, Wesson D, Sitprija V, Johnson RJ. Thiazide-induced subtle renal injury not observed in states of equivalent hypokalemia. Kidney Int. 2007 Dec;72(12):1483-92. doi: 10.1038/sj.ki.5002564. Epub 2007 Oct 10.
PubMed 17928827Reungjui S, Roncal CA, Mu W, Srinivas TR, Sirivongs D, Johnson RJ, Nakagawa T. Thiazide diuretics exacerbate fructose-induced metabolic syndrome. J Am Soc Nephrol. 2007 Oct;18(10):2724-31. doi: 10.1681/ASN.2007040416. Epub 2007 Sep 12.
PubMed 17855639Kim KM, Henderson GN, Frye RF, Galloway CD, Brown NJ, Segal MS, Imaram W, Angerhofer A, Johnson RJ. Simultaneous determination of uric acid metabolites allantoin, 6-aminouracil, and triuret in human urine using liquid chromatography-mass spectrometry. J Chromatogr B Analyt Technol Biomed Life Sci. 2009 Jan 1;877(1-2):65-70. doi: 10.1016/j.jchromb.2008.11.029. Epub 2008 Nov 25.
PubMed 19081307Kim KM, Henderson GN, Ouyang X, Frye RF, Sautin YY, Feig DI, Johnson RJ. A sensitive and specific liquid chromatography-tandem mass spectrometry method for the determination of intracellular and extracellular uric acid. J Chromatogr B Analyt Technol Biomed Life Sci. 2009 Jul 15;877(22):2032-8. doi: 10.1016/j.jchromb.2009.05.037. Epub 2009 May 27.
PubMed 19520625Fravel MA, Ernst ME. Management of gout in the older adult. Am J Geriatr Pharmacother. 2011 Oct;9(5):271-85. doi: 10.1016/j.amjopharm.2011.07.004. Epub 2011 Aug 17.
PubMed 21849262
Study at a glance
From the registry record, last updated by the sponsor on 26 Jul 2013. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Uric Acid and Hypertension in African Americans
- ClinicalTrials.gov ID
- NCT00241839
- Acronym / sponsor ID
- 332
- Conditions
- Cardiovascular Diseases, Heart Diseases, Hypertension
- Phase
- Phase 3
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 150 participants (actual)
- Lead sponsor
- University of FloridaUniversity, hospital or other
- Study start
- Aug 2005
- Primary completion
- May 2011 (actual)
- Study completion
- May 2011 (actual)
- First posted
- 19 Oct 2005 (estimated)
- Results
- Posted 17 Jul 2013
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
This study will test the hypothesis that the administration of a xanthine oxidase inhibitor (allopurinol) will prevent thiazide-induced hyperuricemia, which will result in better blood pressure (BP) control in African Americans.
Detailed description
Thiazide diuretics when used in the treatment of hypertension are associated with many metabolic side effects, including hyperuricemia, gout, insulin resistance, and hyperlipidemia. Each of these conditions is already highly prevalent in African Americans. Our hypothesis is that thiazide-induced hyperuricemia decreases the efficacy of thiazides in controlling BP, leads to endothelial dysfunction, and increases the incidence of insulin resistance and impaired glucose tolerance. This hypothesis will be tested in a randomized, double-blind, placebo-controlled clinical trial of 8-10 weeks duration in which a total of 100 African American patients with hypertension will be enrolled, randomized, and treated as follows:
- Subjects with untreated stage I hypertension will receive chlorthalidone (25 mg/day) and potassium chloride (40 mEq/day) for 4 weeks. Serum potassium levels will be obtained after four weeks on chlorthalidone. If the level is below 3.5 mEg/L, a bolus of 40 mEq potassium 2 to 3 times daily will be given for 2 to 3 days, or as clinically indicated. A maintenance dose of 50 mEq will be initiated. After at least 7 days, they will then be randomized to add-on allopurinol (300 mg/day) or placebo. Treatment will continue for 8-10 weeks with the chlorthalidone, potassium chloride, and allopurinol/placebo regimen.
- Subjects with hypertension controlled (i.e. BP <140/90) or no higher than stage 1 hypertension (i.e., <160/100) on a single antihypertensive agent or two antihypertensive agents will be switched from their prior antihypertensive agent to chlorthalidone 25 mg/day, and potassium chloride (40mEq/day) for 4 weeks. Serum potassium levels will be obtained after four weeks on chlorthalidone. If the level is below 3.5 mEg/L, a bolus of 40 mEq potassium 2 to 3 times daily will be given for 2 to 3 days, or as clinically indicated. A maintenance dose of 50 mEq will be initiated. After at least 7 days, they will then be randomized to add-on allopurinol (300 mg/day) or placebo. Treatment will continue for 8-10 weeks with the chlorthalidone, potassium chloride, and allopurinol/placebo regimen.
The allopurinol (or placebo) dose will be adjusted to achieve serum uric acid levels between 4 and 5.5 mg/dL after 2 weeks on drug. All subjects will receive a low-sodium diet. The primary endpoint is reduction in systolic BP. Secondary endpoints measure endothelial function, ambulatory blood pressure, body composition, systemic inflammation, metabolic parameters, oxidant stress, and renal hemodynamics.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Double blind (participant, investigator)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| A | Active comparator | Drug: Allopurinol, Drug: Chlorthalidone, Drug: Potassium chlorideChlorthalidone 25 mg and Potassium Chloride 40-50meq were given daily for 5 weeks before baseline visit for testing. After baseline testing was completed, Allopurinol 300mg daily was added for 8-10 weeks at which time testing was repeated. |
| B | Placebo comparator | Drug: Placebo, Drug: Chlorthalidone, Drug: Potassium chlorideChlorthalidone 25 mg and Potassium Chloride 40-50meq were given daily for 5 weeks before baseline visit for testing. After baseline testing was completed, a Placebo,matched in appearance to Allopurinol, was added daily for 8-10 weeks, at which time testing was repeated. |
Who may qualify
- Ages
- 18 to 65 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (7 listed)
- African American (including black individuals born in the Caribbean, Africa, Canada, etc.)
- Are either untreated with any antihypertensive agent, with an average sitting clinic BP of between 140/90 and 159/99 mm Hg OR subjects with hypertension controlled (i.e. BP less than 140/90) or no higher than stage 1 hypertension (i.e., less than 160/100) on a single antihypertensive agent or two antihypertensive agents (individuals on fixed dose ARB-diuretic or ACEI-diuretic combinations will also be considered as being on monotherapy for purposes of the study. Individuals on beta blockade or calcium channel blockade for coronary artery disease and/or arrhythmia will not be eligible for the study)
- Random spot urine protein/creatinine ratio of less than 0.5 (approximates a 24-hour urinary protein excretion of 500 mg/day)
- Calculated MDRD GFR of greater than or equal to 60 ml/min/1.73/m^2
- No allopurinol or probenecid intake for at least one month prior to study entry
Key exclusion criteria (15 listed)
- History of malignant or accelerated hypertension
- Confirmed total white cell count of less than 2,500/mm^3, anemia, or thrombocytopenia
- Known history of liver disease
- Known secondary cause of hypertension
- Known presence of diabetes or fasting blood glucose greater than or equal to 126 mg/dL
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| AllopurinolAlso: ZyloprimAllopurinol (300 mg capsule) was given for 8-10 weeks compared to placebo group after initial baseline testing. After two weeks on the Allopurinol, a serum uric acid level was obtained. If the uric acid level was greater than 5.5, the Allopurinol dosage was increased to 600mg (two 300 mg capsules)for the duration of the trial, 6-8 weeks. | Drug | A |
| PlaceboAlso: sugar pillPlacebo capsule (matched in appearance for Allopurinol and labeled 300mg) was given for 8-10 weeks compared to the Allopurinol group after initial baseline testing. After two weeks on the placebo, a serum uric acid level was obtained. If the uric acid level was greater than 5.5, the placebo dosage was increased to 600mg (two 300 mg capsules)for the duration of the study, 6-8 weeks. | Drug | B |
| ChlorthalidoneChlorthalidone 25 mg was given daily for 5 weeks before baseline visit for testing and continued through out the study. | Drug | A, B |
| Potassium chloridePotassium Chloride 40-50meq was given daily for 5 weeks before baseline visit for testing and continued through out the study. | Drug | A, B |
Primary outcome
Change in Diastolic Blood Pressure by Cuff 8-10 Weeks Minus Baseline
Time frame: Measured at 8-10 weeks on allopurinol / placebo
The Diastolic BP was taken at Baseline and after 8-10 weeks of treatment or placebo while on chlorthalidone and potassium chloride. The blood pressure was measured according to "Shared Care" protocol: 15 minutes of quiet, undisturbed rest with three BP measurements obtained subsequently at 5 minute intervals. The mean of the second and third reading was the value used for analysis for both the Baseline measurement and the measurement after 8 - 10 weeks of treatment. The dependent variable is baseline value minus ending value. Measures are in millimeters of mercury (mm hg)
Change in Systolic Blood Pressure by Cuff After 8-10 Weeks Minus Baseline
Time frame: Measured at 8-10 weeks on allopurinol or placebo
The systolic BP was taken at Baseline and after 8-10 weeks of treatment on placebo, while on chlorthalidone and potassium chloride. The blood pressure was measured according to "Shared Care" protocol: 15 minutes of quiet, undisturbed rest with three BP measurements obtained subsequently at 5 minute intervals. The mean of the second and third reading was the value used for analysis for both the Baseline measurement and the measurement after 8 - 10 weeks of treatment. The dependent variable is baseline value minus ending value. Measures are in millimeters of mercury (mm hg)
2 secondary outcomes
Change in Overall Mean BP From Those Obtained by 24 Hour Ambulatory Blood Pressure Measurements (ABPM) 8-10 Weeks Minus Baseline.
Time frame: Baseline and end of treatment (8-10 weeks on allopurinol / placebo)
Change in Uric Acid (UA) Levels: Baseline Less End of Treatment
Time frame: Baseline UA levels compared to end of treatment levels (8-10 weeks on allopurinol / placebo)
Results and safety
Loading the posted results from ClinicalTrials.gov…
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 26 Jul 2013.
- Posted resultsParticipant flow, baseline, all outcome measures and adverse events.
- Background: PubMed 17921363Johnson RJ, Segal MS, Sautin Y, Nakagawa T, Feig DI, Kang DH, Gersch MS, Benner S, Sanchez-Lozada LG. Potential role of sugar (fructose) in the epidemic of hypertension, obesity and the metabolic syndrome, diabetes, kidney disease, and cardiovascular disease. Am J Clin Nutr. 2007 Oct;86(4):899-906. doi: 10.1093/ajcn/86.4.899.
- Background: PubMed 20871636Nakagawa T, Johnson RJ. Hypertension: Is there a dark side to thiazide therapy for hypertension? Nat Rev Nephrol. 2010 Oct;6(10):564-6. doi: 10.1038/nrneph.2010.114. No abstract available.
- Background: PubMed 16598194Nakagawa T, Kang DH, Feig D, Sanchez-Lozada LG, Srinivas TR, Sautin Y, Ejaz AA, Segal M, Johnson RJ. Unearthing uric acid: an ancient factor with recently found significance in renal and cardiovascular disease. Kidney Int. 2006 May;69(10):1722-5. doi: 10.1038/sj.ki.5000391.
- Background: PubMed 17928827Reungjui S, Hu H, Mu W, Roncal CA, Croker BP, Patel JM, Nakagawa T, Srinivas T, Byer K, Simoni J, Wesson D, Sitprija V, Johnson RJ. Thiazide-induced subtle renal injury not observed in states of equivalent hypokalemia. Kidney Int. 2007 Dec;72(12):1483-92. doi: 10.1038/sj.ki.5002564. Epub 2007 Oct 10.
- Background: PubMed 17855639Reungjui S, Roncal CA, Mu W, Srinivas TR, Sirivongs D, Johnson RJ, Nakagawa T. Thiazide diuretics exacerbate fructose-induced metabolic syndrome. J Am Soc Nephrol. 2007 Oct;18(10):2724-31. doi: 10.1681/ASN.2007040416. Epub 2007 Sep 12.
- Background: PubMed 19081307Kim KM, Henderson GN, Frye RF, Galloway CD, Brown NJ, Segal MS, Imaram W, Angerhofer A, Johnson RJ. Simultaneous determination of uric acid metabolites allantoin, 6-aminouracil, and triuret in human urine using liquid chromatography-mass spectrometry. J Chromatogr B Analyt Technol Biomed Life Sci. 2009 Jan 1;877(1-2):65-70. doi: 10.1016/j.jchromb.2008.11.029. Epub 2008 Nov 25.
- Background: PubMed 19520625Kim KM, Henderson GN, Ouyang X, Frye RF, Sautin YY, Feig DI, Johnson RJ. A sensitive and specific liquid chromatography-tandem mass spectrometry method for the determination of intracellular and extracellular uric acid. J Chromatogr B Analyt Technol Biomed Life Sci. 2009 Jul 15;877(22):2032-8. doi: 10.1016/j.jchromb.2009.05.037. Epub 2009 May 27.
- Derived from this study: PubMed 21849262Fravel MA, Ernst ME. Management of gout in the older adult. Am J Geriatr Pharmacother. 2011 Oct;9(5):271-85. doi: 10.1016/j.amjopharm.2011.07.004. Epub 2011 Aug 17.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Mark S. Segal, MD, PhD principal investigator
University of Florida
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 3 study testing Allopurinol, Chlorthalidone and Potassium chloride in people with Cardiovascular Diseases and Heart Diseases, run by University of Florida at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 7 inclusion and 15 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 26 Jul 2013. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 3 studies compare the treatment with the current standard treatment or a placebo in a large group, to confirm how well it works and watch for side effects.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
Yes. Results are posted in the registry (first posted 17 Jul 2013). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Change in Diastolic Blood Pressure by Cuff 8-10 Weeks Minus Baseline (time frame: Measured at 8-10 weeks on allopurinol / placebo). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT00241839, which also lists 8 linked publications.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 26 Jul 2013; AzTrials last refreshed its copy on 7 Nov 2026.