Chapters 4, 5, & 9

Question 1

Pharmacokinetics

Answer 1

Study of what happens to the med, how it reaches target cells, how the body handles the drug.

Absorption
Distribution
Metabolism
Excretion

Question 2

Absorption

Answer 2

Stomach to blood
Skin to blood
Mucus membrane to blood

IVs or intra arterial administration does not use absorption

Question 3

Distribution

Answer 3

Affected by: amount of blood flow, ability of tissues to store drug, drug and protein binding, blood brain barrier.

Question 4

Metabolism (bio transformation)

Answer 4

How body chemically changes drug molecule
Liver primary site of metabolism
Changes is structure of drug
Some meds increase metabolic activity in liver (enzyme induction) causing increased metabolism
CYP-450 could alter metabolism in certain drugs

Question 5

CYP-450

Answer 5

Hepatic microsomal enzyme system
Determines speed of metabolism
Drugs may compete with binding sites on CYP isozyme- responsible for drug-drug interactions

Question 6

Excretion

Answer 6

Most excreted by kidney (bowmans capsule, renal tubule)
Some excreted by lungs
Some in saliva, sweat, breast milk
Rarely in bile or feces

Question 7

Receptor theory

Answer 7

Receptor is cellular molecule to which a med binds, usually a protein
More receptors=more binding=greater effect
Binding either enhances or inhibits normal cellular function
High intrinsic activity is great binding, strong action
When drugs work without receptors, they change cell membrane or depress membrane excitability

Question 8

Agonist

Answer 8

Binds to and activates receptor

Question 9

Antagonist

Answer 9

Binds to receptor and keeps cell from functioning normally

Antagonist competes with agonist for binding sites

Question 10

Potency

Answer 10

How much is needed to produce therapeutic effect

Determined by drugs affinity for a receptor on cell

Question 11

Efficacy

Answer 11

Measures the greatest effect produced by the drug

The more potent (the greater the efficacy) the more intense the adverse effects