PK ADME Flashcards
What is pharmacokinetics?
study of what body does to drug
What type of relationship does pharmacokinetics deal with?
dose-concentration
how does pharmacokinetics link dose and concentration?
links how the dose delivered affects the concentration within the body
What is pharmacodynamics?
study of what drug does to body
What type of relationship does pharmacodynamics deal with?
concentration-effect relationship
How does pharmacodynamics link concentration and effect?
it determines how the effect varies with concentration achieved
Draw a plasma concentration graph typical of an immediate-release oral dosage form. Label the axes, Cmax, AUC, elimination, therapeutic window, absorption, distribution, elimination, toxic, effect/potency, and no effect
(look at image p 32)
once drug absorbed in, what are the 2 forms of drug in body and are they permanently in these states/ can they change?
free drug
bound drug
eqm so can change
bound drug is sequestered (concealed) in blood, meaning…
cant leave, cant distribute to other compartments and sites to where It needs to act. And not free to do its job
plasma conc/ time curve: difference between IV and IR oral formn curves?
IR oral: drug conc 0% at start
IV: straight into bloodstream, so have some drug at 0min
What does the absorption of ADME describe?
how drug gets from dosage form -> site of action (normally blood)
usually for PK purposes what is the site of action?/ where is the drug measured?
blood
absorption is defined by a rate constant (Ka) and is linked to what?
rate at which drug is absorbed into the blood
what is the term given to the mass of drug that is administered?
dose
how much drug gets into the blood how quickly in an INTACT form?
BA (bioavailability
once drug crossed gut wall it travels across portal vein to what organ for metabolism before reaching the bloodstream?
liver
the apparent volume into which a drug is distributed depending on drug properties?
Vd
why are plasma protein and tissue bound drug molecules not included in the free concentration levels in the blood?
unable to act
drug in liver can be secreted into bile which is then secreted into small intestine, what does this mean for absorption?
reabsorbed
absorption form GI tract is X and Y
complex and dynamic
What does the distribution of ADME describe?
how the drug moves about the body, and how this movement may affect the concentration
What 2 pharmacokinetic parameters relate to distribution?
Vd
plasma/tissue binding
Drug in blood can -> (irreversible go to) to….
receptor binding -> effect
liver, bile + reabsorb/ metabolise
kidney + metabolise
-> excreted
Drug in blood can be <-> (in eqm) to….
drug in…
adipose tissue storage
peripheral tissues (stoage)
drug-plasma protein complex