Clinical Variables Affecting PK Flashcards
Intrinsic Factors
Age, Sex, Race, Disease, Pregnancy
Extrinsic Factors
Environmental Factors, Food and Diet, Drug Interactions
Low Extraction Drug
- Effect of Drug Inhibitor on Free Concentration
Inhibition of drug inhibitor lowers intrinsic clearance
- Free Concentration is higher
Low Extraction Drug
- Effect of Drug Inhibitor on Total Concentration
Inhibition of drug inhibitor lowers intrinsic clearance
- Total Concentration is higher
Low Extraction Drug
- Effect of Renal Impairment on Total Concentration
Uremia causes body to produce less albumin –> More free fraction of drug
- Decreases Total Concentration
Low Extraction Drug
- Effect of Renal Impairment on Free Concentration
Uremia causes body to produce less albumin –> More free fraction of drug
- Stays the same, is not dependent on free fraction
Effects of lowering of albumin
Less albumin means
- Increased MPA clearance
- Increased Free Fraction of Drug
- Decreased Total Concentration
- Free Concentration stays the same
Effects of potent inhibitor
Decreases Intrinsic Clearance
- Means more Free Concentration
- Means more Total Concentration
Codeine and Ultra Rapid Metabolizer
Causes high formation of morphine
- Toxicity
MPA
- Food
Lowers Cmax
Does not affect AUC
Mycophenolate Mofetil vs Mycophenolate Acid
Mofetil is converted into the acid at first pass metabolism
MPA
- Omeprazole
Omeprazole decreases acidity of stomach
- Less conversion of Mofetil into Active acid form
- Decreases oral absorption
MPA
- Antibiotics
Antibiotics decreases enterohepatic recirculation of MPA
- Decreases MPA AUC
MPA
- Steroids
Steroids increase intrinsic clearance of MPA
- Decreases MPA AUC
MPA
- Natural Products
Natural Products decrease intrinsic clearance of MPA
- Increases MPA AUC
