EXAM 1 Flashcards
kinetic homogeneity
The predictable relationship between plasma drug concentration and the concentration at the site of action
–>we assume that the plasma drug conc. directly relate to concentrations in the tissues
biopharmaceutics
the interrelationship of the physicochemical properties of a drug, the dosage form in which the drug is given, and the route of administration on the rate and extent of systemic absorption
pharmacokinetics
study of the time course of the drug process that determines the concentration of drugs in body fluid and tissues over time
clinical pharmacokinetics
The application of PK principles to the safe and effective therapeutic management of drugs in an individual patient
pharmacodynamics
the study of the detailed mechanism of action by which drugs produce their pharmacological effect. Refers to the relationship between the drug conc. at the site of action and the resulting effect
therapeutic drug monitoring
measurement of drug concentrations and assessment and application of the resulting concentrations to design safe and effective drug regimens
population-based mathematical model
determination of parameters based on population PK/PD information, clinical trial data, and patient clinical and/or demographic data
patient-specific mathematical model
the utilization of patient-specific drug concentration data to determine PK/PD parameters and individualize the drug regimen
one compartment model
all uniform distribution
drug dose–> compartment–> elimination
-Absorption is instantaneous and complete
zero order elimination
the amount of drug eliminated does not change with the amount of drug/concentration in the body
-the amount removed remains constant
-the FRACTION of drug eliminated
VARIES
first-order elimination
the amount of drug eliminated in a certain period is directly proportional to the amount of drug in the body
-the FRACTION of a drug eliminated remains CONSTANT
Elimination rate constant
-Ke
-always a negative number
what does the elimination rate constant tell you
the fraction or percentage of the drug dose administered that is removed per unit of time
half-life equation
=0.693/Ke
cmax equation
dose/Vd
elimination rate constant equation
(Ln Cp1/Cp2)/t
Factors affecting drug movement
molecular size and structure
degree of ionization
lipid solubility
binding affinity to serum and tissue proteins
drugs affinity for a tissue component
passive diffusion
rate is proportional to drug concentration gradient, partition coefficient, and SA for absorption
Active transport
carrier mediated
requires a form of energy
facilitated diffusion
carrier mediated
does not require energy
Movement occurs down a concentration gradient
surface area effect on absorption
small surface area=decreased absorption
duodenum and jejunum are optimal for absorption
GI factors that affect drug absorption
surface area
pH
motility
gastric emptying
perfusion
food
disease
bioavailability
fraction of the unchanged drug dose that is absorbed from the drug product and reaches the systemic circulation
bioavailability equation
F=amount of drug reaching systemic circulation/total amount of drug dose