Pharmacokinetics Flashcards
What is the therapeutic index?
a measure of drug safety, ratio between the drug/ concentration of the drug producing toxicity and the dose/ concentration that produces a therapeutic effect
What does a large therapeutic index mean?
more favourable margin of safety in the drug
What does the area under the curve mean?
overall exposure of the body to the drug, reflects the amount absorbed into the bloodstream and how long the drug stays in the system
‘bioavailability’
What is volume of distribution defined as?
the theoretical volume needed to dilute the total amount of drug in the body at a given time to acheive the measured plasma concentration
What is drug clearance defined as?
the volume of plasma that is completely cleared ofa drug per unit time
What is steady-state concentration?
concentration of the drug in the plasma reached when the rate of drug absorption is equal to the rate of drug elimination following repeated or continuous dosing
What do zero and first order kinetics refer to?
changes to the amount of a drug as a function of time
What is zero order elimination?
a constat amount of drug eliminated per unit of time
What is first order elimination?
a constant fraction of a drug is eliminated per unit time- as the concentration drops, the elimination rate drops as well
What is the drug elimination half life?
the time taken for the drug plasma concentration to decrease by 50%, calculated during the elimination phase
