Introduction

Question 1

Describe the 2 phases in the plasma concentration curve

Answer 1

Distribution-immediately after administration of the drug

-drug moves from central to peripheral compartments

Elimination phase-more gradual as drug is removed from circulation

Question 2

how does the degree of protein binding relate to volume of distribution?

Answer 2

Inversely proportional

Drugs bound to proteins have low volume of distribution

Question 3

Which drugs bind to albumin?

Answer 3

Acidic

Question 4

Which drugs tend to bind to alpha-1-acid glycoproteins?

Answer 4

basic drugs–local

Question 5

How does binding to protein affect ability to cross cell membrane and elimination

Answer 5

Only unbound drug may cross cell membrane.

Free drug will be more available for elimination

Question 6

Are protein bound drugs inert?

Answer 6

No,law of mass action shows that since reactions are occuring, protein bound drugs will be released as free drug is metabolized to keep equilibrium

Question 7

What are the two factors that determine the ionization of a drug?

Answer 7

pKa of substrate

pH of surrounding fluid

Question 8

If a drug has a pKa of 4.4 and is placed into a solution with a pH of 4.4 how does it ionize?

Answer 8

50% ionized, 50% non-ionized

Question 9

What is ion trapping?

Answer 9

Occurs when a membrane separates 2 areas of differing pHs (stomach, renal tubules, placenta)

Nonionized portion of the drug will diffuse and equilibrate, but the ionized form cannot

Thus a large concentration differrence exist between the membrane

Question 10

What is clearance?

Answer 10

Removal of drug from plasma

Question 11

What is metabolism

Answer 11

enzymatic alteration of a drug’s chemical structure

Question 12

WHat are the 4 major types of metabolic reactions for drugs?

Answer 12

oxidation

reduction

conjugation

hydrolysis

Question 13

What is the difference between pharmacodynamics and pharmacokinetics?

Answer 13

Pharmacodynamics–what the drug does to the body

This included intrinsic sensitivity/responsiveness of the body’s receptors to a drug

Pharmacokinetics–what the body does to the drug

This includes absorption, distribution, metabolism, and excretion of drugs

Question 14

What are enantiomers?

Answer 14

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

Question 15

What is the term used to describe a mixture containing both enanitiomers in equal proportions?

Answer 15

Racemic

Question 16

What is the difference in a agonist and antagonist

Answer 16

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

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

Question 17

A(n) ___________-acting receptor agonist combines directly with its receptor to trigger its physiologic response, while a ___________-acting receptor agonistproduces its physiologic response by increasing the concentration of ENDOGENOUS substrate at receptor site

Answer 17

direct

indirect

Question 18

What is the difference between competitive and noncompetitive antagonism?

Answer 18

In competitive antagonism the receptor inhibition can be overcome by increasing the concentration of the agonist at the receptor

In noncompetitive antagonism inhibition CANNOT be overcome by increasing the concentration of the agonist

Question 19

A small dose gives an exaggerated effect

Answer 19

hyperactive

Question 20

An allergic reaction

Answer 20

hypersensitive

Question 21

Situation where an exceptionally large dose is required to produced the desired/expected pharamcologic effect

Answer 21

hypo reactive

Question 22

tolerance develops within a few doses of a drug. Having to increase the dose to get the same effect

Answer 22

tachyphylaxis

Question 23

the effect of two chemicals taken together is greater than the sum of their separate effect

Answer 23

Synergistic effect

Question 24

the effect of two chemicals taken together is less than the separate effect of either alone

Answer 24

antagonistic effect

Question 25

the effect of two chemicals taken together is equal to the sum of their separate effects

Answer 25

Additive effect

Question 26

What is a prodrug

Answer 26

A biologically inactive compound that can be metabolized in the body to produce a drug

Question 27

Of the 3 routes of enteral administration, which is subject to first pass effect

Answer 27

The three routes are oral, rectal and sublinqual. Oral subject to first pass

Question 28

What is the central compartment and at what speed does it uptake drug

Answer 28

Rapid uptake

Includes IV fluid, and highly vascularized tissues such as heart, brain, kidneys and liver.

Drugs will equilibrate between compartments and eventually be eliminated from the central compartment

Question 29

what is the peripheral compartment? how quickly does it take up drug?

Answer 29

Slow uptake

Includes les vasuclar tissus like fat, bone, and inactive skeletal muscle

Question 30

What is the volume of distribution?

Answer 30

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