pharmacokinetics Flashcards
the four process of pharmacokinetics
absorption
distribution
metabolism
excretion
movement of drug from site of administration to systemic circulation
absorption
movement of drug from the systemic circulation to the site of drug action
distribution
enzymatic alteration of drug structure
metabolism
removal of the drug from the body
excretion
The strength of attraction between a drug and its receptor
affinity
Drug’s ability to cause the receptor to activate after binding to the site
activation
drugs that bind to the receptor site and mimic the action of the endogenous regulatory molecule
agonists
drugs that block the action of the endogenous regulatory molecule (prevent activation)
antagonist
Drugs that bind to the receptor site and have only a moderate expression of the endogenous regulatory molecule
partial-agonists
protein bound drugs are active or inactive?
inactive
families of enzymes that metabolize drugs
CYPs
Inhibits CYP 450
grapefruit juice
increases rate of metabolism
CYP induction
decreases rate of metabolism
CYP inhibition
drugs that are metabolized by CYP 450 enzymes - drugs being acted on or being observed in chemical reaction
substrates
Amount of time it takes for a drug at peak level to be reduced by 50%
half life
A drug that is inactive until it is metabolized
can be useful to break blood brain barrier
Prodrug
Rapid hepatic inactivation of certain oral drugs
Liver reduces dose
First pass effect
Extensive metabolizer
Normal metabolizer (make normal amount of metabolic enzymes
poor metabolizer
genetic factors decrease amount of metabolic enzymes
people who have duplicate copies of genes that make more than normal metabolic enzymes
ultra rapid metabolizers
primary organ of excretion
kidneys
Three criteria of teratogen
- The drug must cause a characteristic set of malformations.
- It must act only during a specific window of vulnerability.
- The incidence of malformations should increase with increasing dosage and duration of exposure.