Exam 3 - Hussein Flashcards
What is the major organ for drug elimination?
Kidneys
What factors contribute to renal clearance?
- Glomerular filtration
- Tubular secretion
- Tubular reabsorption
How is renal clearance calculated?
Renal Cl = Glomerular filtration + Tubular secretion - Tubular reabsorption
The kidneys receive what % of cardiac output?
25%
What is the normal GFR for a healthy adult?
125 mL/min
The glomerulus can filter what small molecules with a molecular weight of?
MW
How does a GFR correlate with an individual’s BSA and free fraction of drug in their plasma?
Proportionally
How is GFR assessed?
Calculation of CrCl over 24 hours of urine collection
What is the equation for CrCl?
CrCl (mL/min) = Cr excretion rate (mg/dL) / [serum concentration (0.8-1.2 mg/dL) * 1440]
How can CrCl be practically calculated to quickly estimate kidney function in clinical practice?
Using ONLY ONE measurement of serum creatinine, CrCl can be calculated via several equations
What is the Cockcroft-Gault equation for CrCl?
CrCl (mL/min) = [(140 - Age)(Weight)] / [(72)(SCr)]
**Multiply entire right side of equation by 0.85 for female over 18 years
In the assessment of active tubular secretion, a transport process AGAINST a concentration gradient, requires what?
Energy
When assessing tubular reabsorption, can be influenced by what?
Tubular pH
pKa of the drug
Unionized drugs are:
More lipid soluble and easily reabsorbed
Ionized drugs are:
More water soluble, not easily reabsorbed, and eliminated more quickly in urine
Is amphetamine a weak acid or weak base?
Amphetamine is a weak base