Drug elim Flashcards
what is drug elimination
metabolism + excretion
what is metabolism
biotransformation - changes in chemical structure
how does biotranformation usually help excretion
make drug more water soluble
what is most important organ
liver
what is a metabolite
final product of biotransformation
what is inactivation
reduction of a drug into molecule that does nothing
what is a prodrug
an inactive drug that when trasnformed become active (codeine to morphine)
what are toxic metabolites
drug metaboites that when transformed are toxic
what are reactive metabolites
dangerous because can react with other macromolecules and create toxicity
what is altered pharmacologic specificity
creates a metabolite with similar activity
**what are 2 types of metabolic enzymes and what do they do
phase 1 - oxidation, reduction, hydrolyses
phase 2 - conjugation (add stuff)
what is enterohepatic circulation
metabolite gets reactived to parent compount (extends the life of drug)
what is formula for clearance rate
Cl = rate of drug elim/plasma drug [c]
what are high vs. low extraction drugs
describes the relative rate at which a drug is removed
what is a high extraction drug
governed by rate of flow to liver - get them out the first time
what is low extraction drug
rate is governed by ability of enzymes to break it down
3 factors involved in renal clearance
- glomerular filtration
- renal tubular secretion
- renal tubular reabsorbtion
what is formula for renal clearance
filtration+secretion- absorption
what does Cl > GFR mean
something helping transpiort drug out
what is total body clearance rate
takes into account all forms of elimination
what is elim. half life
time it takes to elim 1/2 inital [c]
what is t0.5 formula
ln2/K
how many half-lives to elim a drug
5
what is zero order elim
constant rate is eliminated per unit time
