Intro Pharm Basics

Question 1

Enteral route

Answer 1

Oral (PO), rectal, sublingual and buccal

Question 2

Parenteral route

Answer 2

Intravenous (IV), intramuscular (IM), subcutaneous (SC), intrathecal, intraperitoneal, intraosseous

Question 3

What is the only limiting factor in PASSIVE DIFFUSION

Answer 3

membrane thickness

Question 4

What does BBB restrict

Answer 4

the entry of polar and ionized molecules

Question 5

Blood brain barrier

Answer 5

Tight junctions and P-glycoproteins

also astrocytes

Question 6

Blood placental barrier

Answer 6

epithelial and endothelial cells; p-glycoproteins

Question 7

Blood testicular barrier

Answer 7

Tight junctions; P-glycoproteins

Question 8

What mechanisms are responsible for the reduction of drug concentration

Answer 8

Metabolism + Excretion

Question 9

What drugs are generally inactive and more readily excreted than the parent molecule?

Answer 9

Conjugated drugs

Question 10

First pass metabolism

Answer 10

Drugs absorbed from gut go directly to hepatic portal vein –> metabolized in liver and many become inactive before entering primary circulation

Question 11

Important Microsomal CYP450

Answer 11

CYP3A4 - more than half of all microsomal drug oxidations

CYP3A4 + CYP2D6 = ~75% of prescription drugs that undergo oxidation

Question 12

P-450 inducers

Answer 12

phenobarbital, rifampin, phenytoin, carbamazepine, St. John’s wort

Question 13

P-450 inhibitors

Answer 13

Cimetidine, ketoconazole, ritonavir

Question 14

CYP450 metabolism explanation NON PRODRUG

Answer 14

nonprodrug becomes inactive during metabolism; inducer - speeds up metabolism –> less drug to produce clinical response

inhibitor - slows down metabolism –> supra-therapeutic effects

Question 15

CYP450 metabolism for PRODRUGS

Answer 15

Prodrugs are inactive until they are metabolized; inducer speeds up metabolism –> supra-therapeutic effects
Inhibitor slows down metabolism –> less clinical effects

Question 16

infants and elderly populations have ___ renal function meaning…

Answer 16

slow; doses need to be adjusted

Question 17

Drugs that are __________ will have a low rate of glomerular filtration

Answer 17

highly protein bound

Question 18

Is active tubular secretion affected by plasma protein binding?

Answer 18

no

Question 19

Passive tubular secretion depends on ___

Answer 19

lipid solubility of a drug

Question 20

Biliary excretion

Answer 20

compounds with high molecular weights
Conjugation increases biliary excretion
Drugs excreted in the bile may be reabsorbed

Question 21

What does the area under the curve represent

Answer 21

bioavailability

Question 22

What is a good indicator of renal drug clearance?

Answer 22

creatinine clearance

Renal drug clearance higher than creatinine clearance indicates tubular secretion
Renal drug clearance lower than creatinine clearance indicates reabsorption or highly protein bound

Question 23

When elimination is equal to administration, what has been achieved?

Answer 23

Steady state concentration

Question 24

a doubled dose results in a

Answer 24

double steady-state concentration

Question 25

if you increase the frequency by 2x

Answer 25

you double the steady state concentration

Question 26

Agonist

Answer 26

a drug/chemical (ligand) that binds to a receptor and activates it

a drug that has receptor affinity and efficacy

Question 27

Antagonist

Answer 27

a drug (ligand) that binds to the receptor and produces no effect 
sometimes called a "receptor blocker"

a drug that has receptor affinity without efficacy

Question 28

Inverse Agonist

Answer 28

a drug that binds to a receptor and produces a response that is opposite to that of an agonist

decreases the rate of signal transduction

Question 29

Ways to classify drug receptors

Answer 29

according tot he ligand with which they interact (most common)
According to signal transduction mechanisms (second most common)
According to location in cell (least common)

Question 30

Desensitization

Answer 30

decreased ability of receptor to respond to stimulation

Question 31

Inactivation

Answer 31

loss of ability of receptor to respond to stimulation

Question 32

Refractory

Answer 32

after a receptor is stimulated, a period of time is required before the next drug-receptor interaction can produce an effect

Question 33

Down-regulation

Answer 33

repeated or persistent drug-receptor interaction results in removal of the receptor

Question 34

Tolerance

Answer 34

reduced responsiveness to repeated drug administration

Question 35

Tachyphylaxis

Answer 35

rapidly acquired tolerance

Question 36

law of mass action

Answer 36

number of receptors accompanied by a drug depends on the concentration and then association and dissociation rate constants

Question 37

efficacy

Answer 37

the ability of a drug to produce an effect

note that a drug with a lower affinity can still produce a significant response

Question 38

Full agonist

Answer 38

maximal response possible for target tissue

Question 39

Partial agonist

Answer 39

can only produce a sub-maximal response, regardless of the level or binding affinity

Question 40

YOU’RE DOING GREAT

Answer 40

QUEEN

Question 41

competitive antagonist

Answer 41

bind to the exact same site on the receptor as the agonist

Question 42

non-competitive antagonist

Answer 42

block the agonist site irreversibly by binding to a separate site from the agonist

usually forms a covalent bond
shifts the dose-response curve to the right, but also reduces maximal response
effects cannot be overcome by greater doses of an agonist

Question 43

Median effective dose

Answer 43

dose of a drug that produces 50% of maximal response

greater affinity requires a lower dose to occupy 50% of the receptors