pharmacokinetics Flashcards
pharmacokinetic terms: define the terms: first-pass metabolism; enterohepatic circulation; drug half-life; apparent volume of distribution; bioavailability; drug clearance
define bioavailability and what stage it is linked to
proportion of administered drug available within body to exert pharmalogical effect; linked to absorption into blood
define apparent volume of distribution and what stage it is linked to
volume in which drug appears to be distributed (indicator of pattern of distribution, so lipid-soluble drug has larger apparent volume of distribution as can diffuse in fat as well as other tissues); linked to distribution
define biological half-life and what stage it is linked to
time taken for drug concentration in blood/plasma to fall to half its original value (linked to metabolism/excretion); important when giving chronic drugs
define blood (plasma) clearance and what stage it is linked to
volume of blood (plasma) cleared of a drug (i.e. from which drug is completely removed) in a unit time; linked to excretion
what is clearance related to, and what is total clearance
related to volume of distribution and rate at which drug is eliminated; total clearance is sum of all clearance processes
