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Trial registered on ANZCTR


Registration number
ACTRN12611000035921
Ethics application status
Approved
Date submitted
3/01/2011
Date registered
11/01/2011
Date last updated
15/04/2014
Type of registration
Prospectively registered

Titles & IDs
Public title
Drugs and kidney function in the older age group
Scientific title
Drug handling in the older age group: The impact of renal tubular function
Secondary ID [1] 253336 0
None
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Analysis of renal tubular function with respect to drug handling in individuals aged >65 years ? 258875 0
Condition category
Condition code
Renal and Urogenital 259016 259016 0 0
Kidney disease

Intervention/exposure
Study type
Observational
Patient registry
Target follow-up duration
Target follow-up type
Description of intervention(s) / exposure
A simple one off administration of a drug cocktail (fluconazole 50mg single oral dose, pindolol 15mg single oral dose, para-aminohippurate 440 mg iv over 1 minute ) given simultaneously to measure tubular secretion and reabsorption is both safe and representative of tubular function. GFR will be measured using standard radioisotope (chromium) labelled EDTA clearance. Using these methods, we will compare a normal (normal plasma creatinine, no known medical conditions) older age group (aged >65) with a matched aged group with mild renal impairment (eGFR < 60 ml/min) as well as a younger normal group (20 -40 yrs). A more accurate estimate of the contribution of renal tubular function for drug handling will allow safer drug prescribing especially in the elderly patients. Participants will be recruited over a 6 month period.
Intervention code [1] 257788 0
Not applicable
Comparator / control treatment
we will compare a normal (normal plasma creatinine, no known medical conditions) older age group (aged >65) with a matched aged group with mild renal impairment (eGFR < 60 ml/min) as well as a younger normal group (20 -40 yrs).
Control group
Active

Outcomes
Primary outcome [1] 259869 0
In clinical practice it is assumed that changes in tubular function parallel changes in GFR. However this may be incorrect.
As most drugs are organic acids, renal tubular handling may play a critical role in the elimination of drugs.
Clearance of these drugs will be determined by analysis of area under receiver operated curves (ROC) and correlated to the GFR clearances.
Timepoint [1] 259869 0
Blood samples wlll be collected at time 0, and 1hr,2hr,4hr,6hr, 24hr post drug administration and timed urine samples (0-3hr, 3-6hr, 6-24hr) will be collected for each participant. The samples will be stored and analysed as a single batch at the completion of the study.
Secondary outcome [1] 268747 0
Nil
Timepoint [1] 268747 0
nil

Eligibility
Key inclusion criteria
Group 1. Normal individuals aged > 65 years with a normal plasma creatinine and calculated creatinine clearance > 60 ml/min.
Group 2. Individuals aged > 65 years with evidence of mild renal impairment (Stage 3 CKD GFR 35 -60ml/min).
Group 3. A younger normal cohort aged 30 – 50 for comparison with group 1.
Minimum age
65 Years
Maximum age
No limit
Gender
Both males and females
Can healthy volunteers participate?
Yes
Key exclusion criteria
Exclusion criteria. Not able to give consent.
Impaired renal function < than 35 ml/min.

Study design
Purpose
Screening
Duration
Cross-sectional
Selection
Defined population
Timing
Prospective
Statistical methods / analysis

Recruitment
Recruitment status
Completed
Date of first participant enrolment
Anticipated
Actual
Date of last participant enrolment
Anticipated
Actual
Date of last data collection
Anticipated
Actual
Sample size
Target
Accrual to date
Final
Recruitment outside Australia
Country [1] 3115 0
New Zealand
State/province [1] 3115 0
Otago

Funding & Sponsors
Funding source category [1] 258259 0
Charities/Societies/Foundations
Name [1] 258259 0
Otago Medical Research Foundation
Address [1] 258259 0
C/o University of Otago
PO Box 56
Dunedin 9054
Country [1] 258259 0
New Zealand
Primary sponsor type
University
Name
University of Otago
Address
C/o University of Otago
PO Box 56
Dunedin 9054
Country
New Zealand
Secondary sponsor category [1] 257424 0
None
Name [1] 257424 0
Address [1] 257424 0
Country [1] 257424 0

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 260234 0
Northern Y Regional Ethics Committee
Ethics committee address [1] 260234 0
3rd floor, BNZ building
354 Victoria St
PO Box 1031
Hamilton 3240
Ethics committee country [1] 260234 0
New Zealand
Date submitted for ethics approval [1] 260234 0
Approval date [1] 260234 0
24/12/2010
Ethics approval number [1] 260234 0
NTY/10/12/2103

Summary
Brief summary
The kidney plays a major role in the handling of most drugs by several mechanisms including filtration and tubular secretion / reabsorption. With renal impairment, modification of drug doses is required. In clinical practise, changes in renal function are estimated according to the creatinine clearance (CrCl) (estimate of glomerular filtration rate [GFR]). The formulae used, include age as a variable that assumes that renal function declines with age alone. It is also assumed that changes in tubular function parallel changes in GFR , but this may not be correct. Given that many drugs are organic acids, tubular secretion / reabsorption are important variables that in the setting of impaired kidney function may significantly alter drug handling.
Previous studies have shown that a simple drug cocktail given simultaneously to measure tubular secretion and reabsorption is both safe and representative of tubular function in younger subjects. Using this method, we will compare a normal (normal plasma creatinine, no known medical conditions) older age group (aged >65) with a matched aged group with mild renal impairment (eGFR < 60 ml/min) as well as a younger normal group (20 -40 yrs). A more accurate estimate of the contribution of renal tubular function for drug handling will allow safer drug prescribing especially in the elderly patients.
Trial website
Nil
Trial related presentations / publications
Nil
Public notes

Contacts
Principal investigator
Name 32046 0
Prof Robert Walker
Address 32046 0
Department of Medicine
Dunedin School of Medicine
University of Otago
PO Box 56
Dunedin 9054
NZ
Country 32046 0
New Zealand
Phone 32046 0
6434740999
Fax 32046 0
6434747641
Email 32046 0
rob.walker@otago.ac.nz
Contact person for public queries
Name 15293 0
Prof Prof Robert Walker
Address 15293 0
Department of Medicine
Dunedin School of Medicine
University of Otago
PO Box 913
Dunedin. 9054
Country 15293 0
New Zealand
Phone 15293 0
+64 3 4740999 Ex 8045
Fax 15293 0
+ 64 3 474 7641
Email 15293 0
rob.walker@otago.ac.nz
Contact person for scientific queries
Name 6221 0
Prof Prof Robert Walker
Address 6221 0
Department of Medicine
Dunedin School of Medicine
University of Otago
PO Box 913
Dunedin. 9054
Country 6221 0
New Zealand
Phone 6221 0
+64 3 4740999 Ex 8045
Fax 6221 0
+ 64 3 474 7641
Email 6221 0
rob.walker@otago.ac.nz

No information has been provided regarding IPD availability
Summary results
Have study results been published in a peer-reviewed journal?
Other publications
Have study results been made publicly available in another format?
Results – basic reporting
Results – plain English summary