pharokinetics Flashcards
4 stages of pharmcokinetics
absorption
distribution
metabolism
elimination
absorption - what are the different ways
- passive diffusion
- facilitated diffusion
- active transport
- endocytosis
What can affect drug absorption
- Ph
- surface area
- blood flow
How do you calculate bioviability of a drug?
AUC oral/AUC iv x 100
What can affect the distribution
- lipophilicity
- blood flow
- capillary permeability
- plasma & tissue binding
- Volume of distribution
How do you calculate volume of distribution?
What does it determine?
Vd = amount of drug in body/concentration of drug in blood plasma.
is the drug going to be highly distributed in the blood or tissue
What are the different ways that drugs are eliminated?
hepatic
renal
bilary
etc
what are the different reaction of Phase 1 at the liver?
what enzyme is involved?
- oxidation
- hydrolysis
- reduction
enzyme is cytochrome p450
Whats seen in phase 2 in the liver
- glutathione conjugation
- acetlyation
- sulfation
- glucoraridation
what are the Cytochrome p450 enzymes inducers?
Phenytoin Carbamazepine Rifampin Alcohol (chronic) Barbiturates St. johns worts
PCRABS
What are the inhibitors of cytochrome P450
grapefruit protease inhibitor azole antifungals Cimetidine Macrolides Amiodarone Non-DHP CCBs
GPACMAN
