Pharmacokinetics Flashcards
Pharmacokinetics vs pharmacodynamics
kinetics = what body does to drug
dynamics = what drug does to body
most oral drug absorption occurs in the…
small intestine, after gut absorption enters portal vein and travels to liver
First pass metabolism is when….
drug extensively metabolized in liver before reaching systemic circulation
Drug absorption, fastest to slowest
IV -> SL -> ODT -> immediate-release tablets -> extended release tablet
Enteric coated drug formulations will…
limit drug degradation in the stomach
If drug has poor absorption, can increase dissolution rate by…
reduce particle diameter which will increase surface area
Poorly soluble drugs are generally…
lipophilic = lipid loving
poor systemic absorption
Freely soluble drugs are generally…
hydrophilic = water loving
good systemic absorption
Bioavailability is….
extent of drug absorption into systemic circulation
How to calculate bioavailability….
area under the plasma concentration time curve (AUC)
factors that impact drug distribution include….
drug lipophilicity
molecular weight
solubility
ionization
protein binding
Factors that favor greater drug distribution include….
high lipophilicity
low molecular weight
unionized status
low protein binding
Primary sites for drug metabolism
gut and liver
Phase I metabolism reactions
oxidation
reduction
hydrolysis
Phase II metabolism reactions
Conjugation
