Lecture 1: Uptake and Distribution Flashcards
What makes up pharmacokinetics
absorption
distribution
metabolism
excretion
What makes up pharmacodynamics
mechanism of action
sensitivity
responsiveness
Pharmacokinetic parameters
elimination half time
bioavailability
clearance
volume of distribution
Central Compartment, CO%, body mass %
heart, lung, brain, liver, kidney
CO - 75%
Body Mass - 10%
Peripheral Compartment, CO%, body mass %
everything else
CO - 25%
Body Mass - 90%
Drugs that the lung uptakes
Lung first pass effect
basic lipophilic drugs
lidocaine, fentanyl, demerol
Blood brain barrier stops what from crossing
ionized water soluble drugs
can be overcome by large dose or head trauma/hypoxemia
Volume of distribution is influenced by:
lipid solubility - directly
plasma protein binding - inversely
molecule size - inversely
What is Vd
how fast the drug gets to all volumes in the body
Vd Equation
dose of drug / plasma concentration before elimination
Elimination Half Time
time to reduce plasma concentration by 50%
directly proportional to Vd
independent of dose given
Elimination Half Life
time to reduce drug in body by 50%
How does drug accumulation occur
when dose interval is less than half life
Distribution phase
alpha phase
central to peripheral compartment
Elimination phase
beta phase
from central to liver/kidney and out of body
