Ignite Creation Date:
2024-05-05 @ 4:37 PM
Last Modification Date:
2024-10-26 @ 9:22 AM
Study NCT ID:
NCT00285805
Status:
COMPLETED
Last Update Posted:
2010-08-24
First Post:
2006-02-01
Brief Title:
The Influence of Rosiglitazone on the Diuretic Effect of Furosemide and Amiloride
Sponsor:
Radboud University Medical Center
Organization:
Radboud University Medical Center
Study Overview
Official Title:
The Influence of Rosiglitazone on the Diuretic Effect of Furosemide and Amiloride A Double-blind Placebo Controlled Cross Over Study
Status:
COMPLETED
Status Verified Date:
2008-10
Last Known Status:
None
Delayed Posting:
No
If Stopped, Why?:
Not Stopped
Has Expanded Access:
False
If Expanded Access, NCT#:
N/A
Has Expanded Access, NCT# Status:
N/A
Acronym:
None
Brief Summary:
Thiazolidinedione derivates TZDs are Peroxisome-Proliferator-Activated-Receptor-γ agonists PPARγ-agonists and enhance insulin sensitivity One of the side effects however is the fact that subjects treated with these drugs seem to be more prone to fluid retention The precise mechanism of rosiglitazone-related fluid retention is unknown but it is clear that either primary or secondary renal sodium retention is part of the mechanism Furthermore in observational studies TZD-related oedema seems to be resistant to loop diuretic therapy The recent finding that rosiglitazone induces upregulation of the epithelial sodium channel ENaC in the kidney could be the explanation for TZD-related fluid retention and the observed resistance to loop diuretics In the present human in-vivo study the following hypothesis will be tested
Rosiglitazone treatment stimulates the activity of ENaC in the distal nephron which enhances the natriuretic effect of amiloride and decreases the natriuretic effect of furosemide in parallel
Rosiglitazone treatment stimulates the activity of ENaC in the distal nephron which enhances the natriuretic effect of amiloride and decreases the natriuretic effect of furosemide in parallel
Detailed Description:
This is a randomized placebo-controlled double-blind single-centre cross-over study with 4 weeks of wash out comparing placebo with rosiglitazone 4 mg bid for 9 weeks treatment periods Randomization of the treatment sequence will be computer-generated with a sequentially driven allocation Randomization and blinding will be performed at the department of Clinical Pharmacy After 8 furosemide and 9 amiloride weeks in each period the end-point experiments will be performed During all visits week 0 4 8 9 of each period adverse events and pill compliance will be recorded In addition physical examination foot volume and bio-impedance measurements will be performed and safety chemical and hematological profiles will be determined Only at start and at 8 weeks in each period glucose insulin and HbA1c are measured All visits and interventions will be performed at the Clinical Research Center Nijmegen CRCN
Furosemide end-point experiment Each participant will attend the hospital at 8 am after an overnight fast and abstinence of alcohol and caffeine for 20 hours delivering a 24-hour urine collection and the present morning voiding The previous three days each participant will adhere to an individualized diet containing 150 mmol of sodium and 80 mmol of potassium prescribed by a dietician First blood will be collected to measure fasting glucose and insulin concentrations Then the subject will be given an individualized breakfast including 1 cup of water Afterwards a brachial vein will be cannulated and connected to a Braunpump 10 mlhr NaCl 09 followed by blood drawing for safety and vascular hormone measurements aldosterone Atrial Natriuretic Peptide ANP Brain Natriuretic Peptide BNP Vascular Endothelial Growth Factor VEGF and renin
A bolus of furosemide 40 mg will be injected through a small cannule in a vein of the contra-lateral arm just after bladder emptying Venous blood samples will be drawn at 0 15 30 45 60 90120 150 180 240 300 360 420 and 480 minutes after bolus injection to measure plasma furosemide levels The participants will be asked to urinate regularly at least hourly The exact time of voiding and the urine volume will be recorded Two urine samples will be taken In one sample sodium and creatinine concentrations will be measured while the other sample will be light-protected and immediately frozen for measurement of furosemide levels later on To prevent dehydration each participant will be asked to drink tap water equal to the volume of diuresis in the previous hour During the test the participant will be sitting on a bed At noon the participant will be offered an individualized lunch After 8 hours each participant will leave the hospital with the instruction to adhere to the diet without fluid restrictions and to collect the urine for up to 24 hours after start of the experiment
Amiloride end-point experiment Until amiloride infusion the procedures will be similar At time point 0 venous infusion of a loading dose of amiloride will be started 150 μgkg in 60 minutes followed by maintenance infusion 020 μgkgmin for 4 hours Amiloride will be obtained as a sterile powder in the form of amiloride HCl2H2O Directly before use the powder will be dissolved in NaCl 09 up to a concentration of 1 mgml and the solution was filtered through a 022 μm Millipore filter Venous blood for measurement of the amiloride concentration will be sampled at 60 180 300 and 420 minutes All the other procedures will be similar to the furosemide experiment
Pharmacokinetic considerations on the amiloride-dose The peak plasma levels 3-4 hours after intake of 10 or 20 mg amiloride are 20 μgL 32 and 38-40 μgL respectively33 These concentrations are well below the half maximal inhibitory concentration IC50 of amiloride for NaH and NaCa2-transporters and the α1-receptor but well above the IC50 for ENaC34 Using the pharmacokinetic characteristics of amiloride35 we calculated the required amiloride infusion in order to reach a steady-state concentration between 30-45 μgL
Exosome extraction
Urinary exosomes will be isolated by ultracentrifugation and ENaC abundance will be measured by immunoblotting as previously described 1936 and normalized to urine creatinine levels 4 µg of protein lysed in Laemmli buffer will be loaded on 8 SDS-PAGE PAGE blotting and blocking of the PVDF membranes will be done as previously described Membrane will be incubated with 14000-diluted affinity-purified rabbit α-ENaC antibody Rossier BC Lausanne Switzerland followed by 15000-diluted goat anti-rabbit IgGs as secondary antibody coupled to horseradish peroxidase Blotting signals will be visualized using enhanced chemiluminescence The samples will be normalized for the expression level of α-ENaC in placebo treatment and indicated as percentage
Furosemide end-point experiment Each participant will attend the hospital at 8 am after an overnight fast and abstinence of alcohol and caffeine for 20 hours delivering a 24-hour urine collection and the present morning voiding The previous three days each participant will adhere to an individualized diet containing 150 mmol of sodium and 80 mmol of potassium prescribed by a dietician First blood will be collected to measure fasting glucose and insulin concentrations Then the subject will be given an individualized breakfast including 1 cup of water Afterwards a brachial vein will be cannulated and connected to a Braunpump 10 mlhr NaCl 09 followed by blood drawing for safety and vascular hormone measurements aldosterone Atrial Natriuretic Peptide ANP Brain Natriuretic Peptide BNP Vascular Endothelial Growth Factor VEGF and renin
A bolus of furosemide 40 mg will be injected through a small cannule in a vein of the contra-lateral arm just after bladder emptying Venous blood samples will be drawn at 0 15 30 45 60 90120 150 180 240 300 360 420 and 480 minutes after bolus injection to measure plasma furosemide levels The participants will be asked to urinate regularly at least hourly The exact time of voiding and the urine volume will be recorded Two urine samples will be taken In one sample sodium and creatinine concentrations will be measured while the other sample will be light-protected and immediately frozen for measurement of furosemide levels later on To prevent dehydration each participant will be asked to drink tap water equal to the volume of diuresis in the previous hour During the test the participant will be sitting on a bed At noon the participant will be offered an individualized lunch After 8 hours each participant will leave the hospital with the instruction to adhere to the diet without fluid restrictions and to collect the urine for up to 24 hours after start of the experiment
Amiloride end-point experiment Until amiloride infusion the procedures will be similar At time point 0 venous infusion of a loading dose of amiloride will be started 150 μgkg in 60 minutes followed by maintenance infusion 020 μgkgmin for 4 hours Amiloride will be obtained as a sterile powder in the form of amiloride HCl2H2O Directly before use the powder will be dissolved in NaCl 09 up to a concentration of 1 mgml and the solution was filtered through a 022 μm Millipore filter Venous blood for measurement of the amiloride concentration will be sampled at 60 180 300 and 420 minutes All the other procedures will be similar to the furosemide experiment
Pharmacokinetic considerations on the amiloride-dose The peak plasma levels 3-4 hours after intake of 10 or 20 mg amiloride are 20 μgL 32 and 38-40 μgL respectively33 These concentrations are well below the half maximal inhibitory concentration IC50 of amiloride for NaH and NaCa2-transporters and the α1-receptor but well above the IC50 for ENaC34 Using the pharmacokinetic characteristics of amiloride35 we calculated the required amiloride infusion in order to reach a steady-state concentration between 30-45 μgL
Exosome extraction
Urinary exosomes will be isolated by ultracentrifugation and ENaC abundance will be measured by immunoblotting as previously described 1936 and normalized to urine creatinine levels 4 µg of protein lysed in Laemmli buffer will be loaded on 8 SDS-PAGE PAGE blotting and blocking of the PVDF membranes will be done as previously described Membrane will be incubated with 14000-diluted affinity-purified rabbit α-ENaC antibody Rossier BC Lausanne Switzerland followed by 15000-diluted goat anti-rabbit IgGs as secondary antibody coupled to horseradish peroxidase Blotting signals will be visualized using enhanced chemiluminescence The samples will be normalized for the expression level of α-ENaC in placebo treatment and indicated as percentage
Study Oversight
Has Oversight DMC:
None
Is a FDA Regulated Drug?:
None
Is a FDA Regulated Device?:
None
Is an Unapproved Device?:
None
Is a PPSD?:
None
Is a US Export?:
None
Is an FDA AA801 Violation?:
None