Drug Dosing in CKD Flashcards
Define GFR
the volume of fluid filtered from the renal glomerular capillaries into the Bowman’s capsule per unit time
The most common and practical way to calculate Cr clearance
serum creatinine (SCr) by a simple blood test
T/F The higher the CrCl the better the kidney function, the higher the serum SCr the worse the kidney function
true
normal SCr
0.6-1.3mg/dL
how do you calculate ideal body weight?
Male 50.0 kg + 2.3kg per inch over 5 feet
Female 45.5kg + 2.3kg per inch over 5 feet
Cockcroft-Gault Equation
CrCl (male) = (140-age) x weight (kg)/ 72 x SCr (mg/dL). CrCl (female) = 0.85 x male CrCl
What happens to CrCl with increased age?
would be lower, decreases with age
What happens to CrCl with increased weight?
would be higher accounting for more muscle mass
How do NSAIDs cause CKD?
constrict afferent arteriole, decreases perfusion
How do aminoglycosides cause CKD?
kill epithelial cells in PCT
How does uremia effect protein binding?
Uremia may inhibit or enhance protein binding, therefore more active drug is in the system
What beta lactam IV antibiotic can induce seizures at high concentrations?
Imipenem
What method is practical to adjust the dosage of drugs with long half lives?
Q 24 hours instead of q 12 hours, dose remains the same
How should you adjust doses for patients who are on dialysis?
Supplemental doses may be required. give after dialysis
At what GFR can you assume dose modification is not necessary?
GFR’s >50
