Principles of Prescribing in Renal Disease Flashcards
what is creatinine?
a breakdown product of muscle
what is creatinine filtered by?
by the glomerulus making it good to use to measure GFR
what are the problems with using the creatinine clearance to measure GFR?
- Creatinine is also excreted by the proximal tubular secretion therefore you get higher creatinine clearance than GFR
2.Rapidly changing CrCl in renal failure is also an issue - Creatinine breakdown in the gut becomes an issue in situations of very
low CrCl - Older patients are not producing creatinine at the same rate and thus
lower levels of SrCr do not properly indicate renal function.
what effect does renal function have on drugs?
- affects drug solubility
- affects metabolite solubility/activity
- may have kinetic issues i.e. fluid volume, plasma protein concentration
- there may be an increase in the amount of drug available to cause an effect
when dealing with chronic renal failure, what effects do we consider?
- Comorbid disease
- Concomitant medications
- GFR
- Filtration
- Tubular secretion and absorption
- Renal metabolism and bioactivation
- Non-renal clearance and distribution
what scale is used to look at the population’s liver failure?
NFK-K/DOQI
what are the different stages of liver failure?
1 - kidney damage with normal or increased GFR
2 - kidney damage with mild or decreased GFR
3 - Moderate or decreased GFR
4 - Severe decreased GFR
5 - Kidney Failure
what two ways are available to measure CrCl or GFR?
- Cockcroft-Gault equation
2. MDRD (Modification of Diet in Renal Disease) equation
which method is preferred to measure older patients CrCl/GFR level?
the MDRD to detect a GFR lower than 90mL/min/1.73m^2
what are the options in renal disease?
- Altered drug choice.
- Dosage adjustment.
- Dosage interval alteration.
what are the 3 GFR bnds used for dosage adjustments?
- <10ml/min/1.73m2
- 10 to 50ml/min/1.73m2
- > 50ml/min/1.73m2
what is the GFR of patients on dialysis?
<10ml/min/1.73m2
