Drug Administration, Absorption, & Distribution Flashcards
when a drug enters the plasma
absorption
the transportation of the drug to and from the sites of action
distribution
when the chemical structure of the drug is changed
biotransformation (metabolism)
irreversible loss of drug
excretion
loss of drug concentration or effect
elimination
what are the 4 common routes of drug administration?
1) enteral (via GI tract)
2) parenteral (via injection)
3) inhalation
4) Local
where does most absorption occur for drugs administered orally?
small intestine (greater surface area)
what are the common parenteral routes of drug administration?
1) intramuscular
2) subcutaneous
what are the 4 main drug transport mechanisms?
1) filtration
2) facilitated diffusion
3) active transport
4) passive diffusion
adding additional reactant to a system will shift the rxn to the ______ , toward the side of the __________
right; products
weak acids undergo greater absorption in a(n) ______ environment
acidic
weak bases undergo greater absorption in a(n) ______ environment
alkaline
what are the factors that affect drug distribution?
- blood perfusion rate
- membrane characteristics
- intra/extracellular pH
- sequestration in fat
- protein binding
weak acids bind to ___________
serum albumin
weak bases bind to __________
glycoproteins
plasma protein binding can lead to …..
- longer duration of action
- sulfonamides will displace bilirubin
- drug-drug interactions
- misinterpretations of drug levels
drugs under _____ MW can passively diffuse across the placental barrier
1000
