Pharmacokinetic Principles Flashcards
manner in which reaction rate is affected by drug concentration
rxn order
decrease in drug concentration with respect to time
rxn rate
which type of rxn is described below?
- rxn rate independent of drug concentration
- linear relationship of drug conc vs time
- slope is rate constant
zero order rxn
which type of rxn is described below?
- rxn rate dependent upon drug conc
- rxn rate constant units are reciprocal time
1st order rxn
amount of time required for drug conc to fall 50%.. reciprocally related to first order rate constant
half-life
alcohol undergoes ____ order elimination
zero
when any enzyme is saturated, it catalyzes the rxn at ____ order rather than ____ order.
zero; first
- rate & extent of absorption
- rate & extent of distribution
- rate & extent of metabolism
- rate & extent of excretion
These are characteristics of what?
blood level vs time curve
what are the parameters of blood level vs time curve
- time to onset of action
- time to peak drug effect
- time to drug effect
latency refers to?
time to onset of action
on the blood level vs time curve, what does ‘F’ represent
fraction of drug dose given orally that reaches systemic circulation
what are the 2 compartments described in the two compartment model?
- central compartment
- peripheral compartment
phase involving rapid clearance from central to peripheral compartment
distribution phase
phase involving overall elimination from central compartment
elimination phase
what do weak acids bind to?
serum albumin
what do weak bases bind to?
glycoproteins
what are the consequences of plasma protein binding?
- longer duration of action
- displacement of bilirubin by sulfonamides
- drug-drug interactions + drug displacement
- misinterpretations of drug levels
what does the variable (Vd) denote?
the apparent volume of distribution
drug binding to tissues _____ apparent volume of distribution
elevates
drug binding to plasma proteins _______ apparent volume distribution
depresses
volume of plasma cleared per unit time… independent of elimination mechanism
drug clearance
dose necessary to maintain steady state plasma concentration
maintenance dose
achieved after approximately four elimination half-lives
steady state plasma concentration
a larger initial dose to quickly establish desired plasma level
loading/priming dose
creatinine plasma concentration and clearance reflect what?
renal function
what is the equation for clearance?
Cl = excretion rate / [plasma]
