pharmacokinetics MT1 Flashcards
this is the branch of pharmacology concerned with the movement of drugs within the body/what the body does to the drug
pharmacokinetics
what are the factors that determine blood concentration of a drug?
- size of administered dose
- extent of absorption
- rate of absorption
- extent od drug distribution
- extent of elimination
- rate of elimination
this is how much of a drug gets absorbed
extent of absorption
what determines the extent of absorption of a drug
formulation
this is how quickly a drug gets absorbed
rate of absorption
what determines the rate of absorption
route
this is how well a drug spreads and goes into organs
extent of drug distribution
what determines the extent of drug distribution
depends partly on volume/site of distrbution
this is how much and how well a drug can leave the body
extent of elimination
this is how quickly the drug can leave the body
rate of elimination
the manner in which a drug is taken is called a __________. this depends on the therapeutic objectives (e.g. cure, prevention, etc.)
dosage regimen
Managing a proper dosing regimen to treatment of patients with various diseases requires the maintenance of enough drug systematic exposure which in an effective range to have a certain duration and intensity of effect, but doesn’t give adverse effects. It is necessary to keep the dosage regimen within the _______________
therapeutic window
this is a model used in determining drug movement in the body; its the simplest way to view the entry, disposition, and exit of the drug from the body where the body acts like a single, uniform compartment
single compartment open model
the rate of change in concentration over time (dC/dt) in the body (reservoir) in a one compartment open model is dependant on these two factors
- how much drug there is in the body (reservoir)
- how well the drug is eliminated
how much drug there is in the body/reservoir depends on what two factors
- the size of the reservoir for the drug
- the dose given
how well the drug is eliminated depends on what two factors
- rate of elimination
- capacity of the elimination organs to remove the drug
What are the two types of elimination processes?
Zero Order elimination/kinetics and First order elimination/kinetics
this elimination process is the mass of the drug that is eliminated/transferred is constant with respect to time
zero order kinetics
this elimination process is the mass of the drug that is eliminated/transferred is never constant with reprint to time
first order kinetics
for a zero order process, drug transfer is at a constant rate, ______________ of the plasma concentration
independant
for frist order process, the rate of drug transfer is not constant and is _________ of the plasma concentration
dependant - the more drug the faster its eliminated
for first order kinetics, the rate of change of concentration with respect to time depends on what two factors
- how much drug there is initially
- the elimination capacity
zero or first order kinetics?
the number of enzymes/receptors is higher than the amount of drug
first order kinetics
zero or first order kinetics?
accumulation of drug in the body leads to toxicity
zero order kinetics
zero or first order kinetics?
there are limited number of enzymes/receptors for the amount of drug
zero order kinetics
zero or first order kinetics?
the rate of transfer does not depend on how much drug is available
zero order kinetics
zero or first order kinetics?
rate of transfer does depend on how much of the drug is available
first order kinetics
we can predict the rate of decline of drugs following first order kinetics using __________
half life
________ is constant for a particular drug following first order kinetics
- this helps to predict the length of time it takes for a drug to leave the body
- it also helps to determine how long its takes to reach a steady state drug levels in the body after multiple dosing
terminal half-life
what is the equation for half life for first order kinetics
t(1/2) = 0.693 Vd/Cl
is half life directly or inversely proportional to Clearance
inversely
is half life directly or inversely proportional to volume distribution
directly
