Chapter 4

Question 1

Pharmacokinetics

Answer 1

how the body handles a medication

Question 2

Four processes of pharmacokinetics

Answer 2

absorption
distribution
metabolism
excretion

Question 3

Plasma membrane

Answer 3

consist of a lipid bi-layer w/ proteins and other molecules
lipophilic
impermeable to large molecules, ions and polar molecules

Question 4

for a drug to take effect, it must:

Answer 4

pass through the plasma membrane
uses diffusion or active transport

**some drugs bind to receptors outside the membrane to take effect

Question 5

Easily cross the plasma membrane

Answer 5

small
non-ionized
lipid soluble
water soluble

Question 6

Difficult to cross the plasma membrane

Answer 6

large

ionized

Question 7

Absorption

Answer 7

movement from site of administration across membranes to circulating fluid

Question 8

factors influencing absorption

Answer 8

route
dose
degree of ionization
interactions

Question 9

Distribution

Answer 9

transport of drug throughout the body

Question 10

Factors effecting distribution

Answer 10

blood flow to tissues
physical properties of the drug
drug-protein complexes
competition for plasma-protein binding sites

Question 11

Distribution barriers

Answer 11

blood-brain barrier

fetal-placental barrier

Question 12

Metabolism

Answer 12

Biotransformation

converting a drug into a form that is more easily removed from the body

Question 13

Sites of metabolism

Answer 13

liver (primary)
kidneys
GI tract

Question 14

Process of metabolism

Answer 14

drugs undergo hydrolysis, oxidation and reduction

Question 15

Conjugation

Answer 15

process of metabolism that causes the addition of side chains to drugs making them more water soluble and easier to excrete.

Question 16

Prodrugs

Answer 16

only become active once metabolized

Question 17

Enzyme induction

Answer 17

process of increasing metabolic activity in the liver

Question 18

First pass effect

Answer 18

drugs reach the liver before their target cell. They are metabolized and rendered inactive

Question 19

Hepatic microsomal enzyme system

Answer 19

used in the liver for metabolism

P-450 system

Question 20

Excretion

Answer 20

removal of drugs

Question 21

Primary site of excretion

Answer 21

kidneys (90%-95%)

Question 22

Sites of excretion

Answer 22

Kidneys
Respiratory
Glandular (sweat, saliva, breast milk)
Biliary excretion

Question 23

Drug plateau

Answer 23

when the level of the drug in the plasma is within a therapeutic range
takes about 4 half lives to reach this