None listed
Conditions
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.
Interventions
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) w
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.
Sponsors
University of Otago
Eligibility
Sex/Gender
All
Age
65 Years to No maximum
Healthy volunteers
Yes
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.
Exclusion criteria
Exclusion criteria. Not able to give consent. Impaired renal function < than 35 ml/min.
Outcome results
None listed