Exam 1 Flashcards
(342 cards)
enteral
absorbed through the GI tract
parenteral
given outside of the GI tract
PO
oral
PR
rectal
SL
sublingual
IV
intravascular or intravenous
IM
intramuscular
SC or SQ
subcutaneous
advantage of parenteral route
more rapid and predictable absorption, useful in unconscious or vomiting person
disadvantage of parenteral admin
needs to be aseptic, could cause pain/irritation, can’t give insoluble drugs via IV, much harder to “take back” a dose once given
what sort of drug will more readily cross plasma membranes
small, non-ionized, lipid soluble drugs
when a drug is absorbed via GI tract what does it go through before entering the systemic circulation
portal circulation aka first pass hepatic metabolism
what happens if a drug is rapidly metabolized in the liver
a smaller amount of the drug in the original unchanged state will reach the target tissues
what kind of drug can the kidney not efficiently eliminate
lipid soluble, so they are reabsorbed from kidney back into systemic circulation
Phase I drug metabolism involves
converting lipid soluble molecules into water soluble by introducing or unmasking a polar group (-OH or -NH2)
Phase I reaction are most frequently catalyzed by
cytochrome P450
Phase II reactions consist of
conjugation, wherein an endogenous polar group is added to a drug molecule (ex: glucuronic acid, sulfuric acid, acetic acid, amino acid) so that it can be excreted from the kidney
bioavailability is
fraction of administered drug that reaches systemic circulation in an unchanged form…(if 100 mg of a drug is taken orally and 70 mg of the drug is absorbed unchanged, then the bioavailability of that drug is 70%)
half life is
the amount of time required for the plasma concentration of a drug to decrease by 50% after discontinuation of a drug
a loading dose is
an initial dose of drug that is higher then subsequent doses for the purpose of rapidly achieving therapeutic drug concentrations in the serum.
efficacy refers to
the degree to which a drug is able to induce maximal therapeutic effects. Efficacy is a term often used to compare drugs of different classes.
potency is
the amount of drug required to produce 50% of the maximal response that the drug is capable of inducing. Potency is a term more frequently used to compare drugs of a similar class.
the EC50 or effective concentration 50 is
the concentration or dosage of an agent which induces a specified clinical effect in 50% of the subjects to which the drug has been administered.
LD50 or lethal dose 50 is
the concentration or dosage of an agent or drug which causes death in 50% of the subjects to which that agent or drug has been administered.