Basic Concepts

Question 1

The specific protein molecule of lipid bilayer of cell membrane with which an administered drug interacts.

Answer 1

receptor

Question 2

KNOW:

Concentration (number) of receptors at site of action may change. True or false?

Answer 2

true

Question 3

Name the receptors in order pictured:

Answer 3

membrane receptor

ligand-gated channel

voltage-gated ion channel

enzyme

Question 4

2 molecules having the same chemical composition but different orientations around a central atom – mirror images are:

Answer 4

entantiomers

Question 5

equal amounts of left- and right-handed enantiomers of a chiral molecule

Answer 5

racemic mixture

Question 6

a drug that produces its clinical effect by binding to a receptor and activating it (mimetic)

Answer 6

agonist

Question 7

a drug that produces its clinical effect by binding to a receptor WITHOUT activating it and simultaneously prevents an agonist from stimulating it (blocking)

Answer 7

antagonist

Question 8

drug that combines directly with its receptor to trigger its physiologic response

Answer 8

directly-acting receptor agonist

Question 9

drug that produces its physiologic response by increasing the concentration of ENDOGENOUS substrate (neurotransmitter or hormone) at receptor site

Answer 9

Indirectly-acting receptor agonist

Question 10

receptor inhibition which can be overcome by INCREASING the concentration of the agonist at the receptor site (reversible blockade)

Answer 10

competitive antagonism

Example: Roc

Question 11

receptor inhibition which CANNOT be overcome by increasing the concentration of the agonist (irreversible blockade)

Answer 11

Noncompetitive

Question 12

Terminology of Drug Responses (8)

Answer 12

Hyperactive
Hypersensitive (allergic)
Hypo reactive (tolerant)
Tachyphylaxis
Additive effect
Synergistic effect
Antagonistic effect
Prodrug

Question 13

Routes of Administration (2)

Answer 13

enteral

parenteral

Question 14

Enteral routes: (3)

Answer 14

• oral
• sublingual–bypass liver and goes directly to heart and systemic circulation
• rectal

Question 15

Parenteral – “aside from” the alimentary tract routes (8)

Answer 15

• Intravenous (IV)
• Intraarterial–very few (calcium blocker for neuro pts to localize vasodilation, for example)
• Intramuscular (IM)–more muscle, faster effect
• Intrathecal–CSF, spinal
• Subcutaneous (SC)
• Nasal
• Pulmonary
• Transdermal, Topical

Question 16

Subcutaneous injection is placed under the _____ layer.

Answer 16

dermal

Question 17

Site-specific factors affecting absorption (3)

Answer 17

Blood flow from site
Surface area for absorption
Solubility of drug at site

Question 18

Ok, so now that it’s in, where does the drug go? (3)

Answer 18

Compartment Model
Volume of distribution
Ionization

Question 19

THEORY: the body is composed of multiple compartments having calculated volumes is known as:

Answer 19

Compartmental Models

Question 20

Compartmental Models

We can examine the pharmacokinetics of drugs we administer in terms of what compartments they travel to (4 + ect.) and what happens when they reach those compartments (clinical effect, metabolism, storage, etc.)

Answer 20

(circulating blood, central nervous system, liver, fat, etc.)

Question 21

Which compartment involves rapid uptake of drug?

Answer 21

Central compartment

Question 22

Central compartment – rapid uptake of drug includes: (6)

Answer 22

intravascular fluid and highly perfused tissues like the lungs, heart, brain, kidneys, and liver

Question 23

This compartment involves slower uptake and includes less vascular tissues like fat, bone, and inactive skeletal muscle.

Answer 23

Peripheral compartment

Question 24

2-Compartment Model

Drugs equilibrate between compartments and are eventually eliminated from the _____ compartment.

Answer 24

central

Question 25

What model?

Answer 25

compartment model

Question 26

What is indicated by this picture?

Answer 26

there is no movement of drug out of the beaker, so the graph shows only a steep rise to maximum followed by a plateau.

Question 27

Answer 27

a route of elimination is present, and the graph shows a slow decay after a sharp rise to a maximum. Because the level of material in the beaker falls, the "pressure" driving the elimination process also falls, and the slope of the curve decreases. This is an exponential decay curve.

Question 28

Answer 28

drug placed in the first compartment ("blood") equilibrates rapidly with the second compartment ("extravascular volume") and the amount of drug in "blood" declines exponentially to a new steady state.

Question 29

Answer 29

illustrates a more realistic combination of elimination mechanism and extravascular equilibration. The resulting graph shows an early distribution phase followed by the slower elimination phase.

Question 30

Which model does this describe? CONCEPT: the total approximation of all the compartments to which a drug goes Relates the amount of drug in the body to the concentration of drug in the blood or plasma

Answer 30

Volume of Distribution

Question 31

This is known as what? Note x and y axis.

Answer 31

Plasma Concentration Curves

Question 32

\_\_\_\_\_\_ Phase – immediately after administration of drug – movement from central to peripheral compartments.

Answer 32

Distribution

Question 33

\_\_\_\_\_\_\_ Phase – more gradual as drug is removed from circulation

Answer 33

Elimination

Question 34

Protein Binding Many drugs travel on proteins in the blood (2)

Answer 34

* albumin--binds acidic drugs and not metabolized in liver, stays in central circulation * alpha-1-acid glycoproteins--binds basic drugs, anesthetics

Question 35

Degree of protein binding is INVERSELY PROPORTIONAL to what?

Answer 35

VOLUME OF DISTRIBUTION

Question 36

\_\_\_\_\_\_\_ drug crosses cell membranes

Answer 36

Unbound

Question 37

\_\_\_\_\_ drug is more available for elimination.

Answer 37

Free

Question 38

KNOW! Drug that is protein bound is pharmacologically inert. True or false?

Answer 38

false NOT inert!

Question 39

The rate of a chemical reaction is directly proportional to the molecular concentrations of the reacting substances is known as what?

Answer 39

law of mass action

Question 40

Whether or not a drug exists predominately in an ionized vs. nonionized state affects how well it permeates membranes is known as:

Answer 40

ionization

Question 41

What determines the degree of ionization of a drug? (2)

Answer 41

pK of substrate pH of surrounding fluid

Question 42

If a membrane separates areas of 2 differing pHs (ex. stomach, renal tubules, placenta), then the nonionized portion of a drug diffuses and equilibrates, but the ionized form does not, so large concentration differences exist on either side of the given membrane. Known as what?

Answer 42

Ion trapping

Question 43

'removal of drug from plasma is known as:

Answer 43

Clearance

Question 44

KNOW: Clearance involves what organs? (2)

Answer 44

* **kidneys** -- ester hydrolysis * **liver ** -- Hofmann elimination, water soluble metabolites Note: Cis is metabolized by Hofmann elimination!

Question 45

Enzymatic alteration of drug’s chemical structure is known as:

Answer 45

metabolism

Question 46

Metabolism – enzymatic alteration of drug’s chemical structure – 4 major types of reactions

Answer 46

oxidation -- conjugation reduction -- hydrolysis

Question 47

When does propofol reach the brain in the flowchart?

Answer 47

Drug concentration at site of action

Question 48

What typeof receptor is a ß-agonist receptor? What type of drug acts on this receptor?

Answer 48

membrane phenylephrine

Question 49

What type of receptor is a GABA (gamma-aminobutyric acid) receptor?

Answer 49

ligand-gated

Question 50

What drug acts on a GABA receptor?

Answer 50

Versed allows the influx of Cl-

Question 51

The Na+ channel receptor is an example of what type of receptor?

Answer 51

voltage-gated ion channel

Question 52

What tyype of drug acts on the Na+ channel?

Answer 52

local anesthetics

Question 53

Phosphodiesterase inhibitors are an example of what type of receptor?

Answer 53

enzyme

Question 54

Milrinone is an example of this type of receptor:

Answer 54

enzyme receptor

Question 55

What type of drug can run out of endogenous substrate (tachyphalaxis)?

Answer 55

ephedrine

Question 56

KNOW Ephedrine is an example of an ______ acting receptor agonist.

Answer 56

indirectly Can run out of substrate--\>tachyphalaxis--\> more drug needed to produce response

Question 57

What is the definition of a hyperactive response to drug?

Answer 57

give a small dose and get an exaggerated response

Question 58

What is the definition of tachyphylaxis?

Answer 58

Have to increase the dose to get the original effect

Question 59

What is the definition of an additive effect of a drug response?

Answer 59

1+1=2 Example: MAC of inhalational agents

Question 60

What is the definition of an antagonistic effect?

Answer 60

Less effect if 2 drugs are combined.

Question 61

What is the definition of a prodrug? What is an example of a prodrug?

Answer 61

Metabolized in the liver and becomes active Morphine or codeine

Question 62

Intraosseous route is preferred when?

Answer 62

Mostly in kids too little to do IV

Question 63

KNOW: 2-Compartment Model The central compartment represents \_\_\_\_% of cardiac output and \_\_\_\_% of body mass.

Answer 63

75 10

Question 64

What does it mean when drug has low Vd?

Answer 64

Wants to stay in the central compartment, like Roc.

Question 65

How much drug stays in the central compartment? ## Footnote What does it mean when drug has high Vd?

Answer 65

Drug wants to redistribute, like propofol.