Flashcards in Lecture 2 & 3 - Pharmacokinetics (PK) and Drug Disposition Deck (131)
what the body does to a drug
*study of how the body absorbs, distributes, metabolizes, and eliminates (ADME) a drug over time
Where does 1st pass effect occur?
Primary site for absorption?
____ ______ is key for distribution
Primary site for metabolism?
Primary site of excretion
What is the clinical goal from using and understanding pharmacokinetics?
Drug effect related to concentration at ??
site of action
For more drugs, the concentration at the site of the _____ determines the intensity of a drug's effect
In order for drugs to move through the body they must cross cell membranes. What are the 3 ways they can do that?
1-pass through channels or pores
2-passing through the membrane with the aid of a transport system
Where are transporters found?
Out of the 3 types of drug movement, which is the most common?
Why does the movement through the body for most drugs depend on ability for direct penetration? (2 reasons)
-most drugs are too large to pass through channels
-most drugs lack transport system to help them cross cell membranes
In order to penetrate cell membranes directly, a drug must be _____
Difference between one and two compartment model?
-drug is administered, immediately distributed, and then can be metabolized and excreted
-some drugs do not distribute instantaneously to all parts of the body
-it goes to individual organs first, and then gets distributed to the peripheral part of the body afterwards
Drugs that don't extensively distribute into extravascular tissues (drugs that aren't stored) are well described as ?
Drugs that do extensively distribute into tissue (drugs that are stored in tissues) are well described as ?
fraction of unchanged (unmetabolized) drug reaching the systemic circulation following administration by any route
inversely proportional to dose lost
Vd (volume of distribution)
measure of apparent space in the body available to contain the drug - how the drug is distributed in the body relative to plasma
clearance refers to ???
metabolism and excretion
Clearance (metabolism and excretion)
measure of ability of the body to eliminate the drug
volume of drug per unit of time that gets excreted
drug half life (T1/2)
time required to change the concentration of the drug present in the body by one half during elimination
AUC admin route / AUC(IV) x 100
AUC oral / AUC injected x 100
accumulation factor = 1/dose lost
amount of drug in body (mg) / conc of drug in plasma (mg/L)
answer expressed in L
Cl = (0.693 / t1/2) x Vd
drug half life (T1/2)
t1/2 = (0.693 X Vd) / Cl