Pharmacokinetics - Quiz 1

Question 1

Absorption

Answer 1

Bioavailability (F): % of medication that reaches systemic circulation

Question 2

What is the bioavailability of IV/IM/SQ meds?

Answer 2

F=1 or 100%

Question 3

If bioavailability for oral Synthroid is 50%, and the dose is 100 mcg, what would your IV dose be?

Answer 3

Bioavailability F=.5
100X.5

50 mcg

Question 4

What does an increase in surface area do to absorption?

Answer 4

the more surface area, the more likely it will be absorbed into the body

Question 5

Where does meds given via SL/buccal drain?

Answer 5

Vena Cava

Question 6

For meds to pass through membrane under tongue, they MUST be

Answer 6

highly lipid soluble and potent

Question 7

When a drug is absorbed across the GI membranes, it enters the hepatic portal system which carries molecules directly to the

Answer 7

Liver

Question 8

Anything given topically needs to be _________ because it needs to cross the skin barrier

Answer 8

lipophilic

Question 9

Temperature does what to absorption?

Answer 9

Increases absorption

Question 10

Why does inhalation cause a rapid effect?

Answer 10

• D/T the large surface area
• Avoids first pass
• Local site of action

Question 11

IV injections have what effect?

Answer 11

Potentially immediate

Question 12

IV/IM/SQ is absorbed through which type of diffusion?

Answer 12

Simple diffusion

Question 13

What is volume of distribution?

Answer 13

Size of compartment necessary to account for the total amount of drug in the body if it were present throughout the body at the same concentration found in the plasma

Question 14

Average adult plasma is how many liters?

Answer 14

about 3

Question 15

What is compartment 1?

Answer 15

systemic system

Question 16

What is compartment 2?

Answer 16

highly vascular organs

Question 17

What is compartment 3?

Answer 17

fatty compartment

Question 18

What do you need to be in order to reach compartment 3?

Answer 18

Highly lipophilic

Question 19

If albumin has bound up your medication molecule, what does that mean?

Answer 19

You will see less of an effect

Question 20

Low albumin levels will cause what in terms of distribution?

Answer 20

It will cause more med floating around, hight potential for toxicity. (albumin is a binder for medication)

Question 21

Fat tissue binds to

Answer 21

lipid soluble drugs

Question 22

Bones bind to

Answer 22

tetracyclines

Question 23

Heart muscle binds to

Answer 23

Digoxin

Question 24

In order to cross the blood brain barrier, you need to be

Answer 24

lipophilic

Question 25

What meds is a fetus exposed to?

Answer 25

nearly all medications a mother takes

Question 26

What are P-glycoproteins?

Answer 26

a giant class of transport proteins all over body that requires ATP

Question 27

What is passive diffusion?

Answer 27

Moves through lipid bilayer with ease, no transport or energy needed.

Question 28

What is facilitated diffusion?

Answer 28

Goes from high concentration to low concentration using carrier protein to get through lipid bilayer. No energy needed.

Question 29

What is aqueous channels?

Answer 29

Where water and electrolytes can move through. No energy or carrier needed.

Question 30

What is active transport?

Answer 30

Move against concentration gradient via a carrier and ATP

Question 31

What is Metabolism

Answer 31

Breakdown for ease of elimination

Question 32

Metabolism may make a drug become a ________?

Answer 32

Prodrug

Question 33

What is a prodrug?

Answer 33

A drug not administered in active form, needs to be metabolized before works. (e.g. propofol)

Question 34

What is phase 1 metabolism?

Answer 34

Induce or expose a functional group on the parent compound. Generally lose activity, rare instances of preserved. Readily eliminated.

Question 35

What is phase 2 metabolism?

Answer 35

Conjugation reactions. | Links parent compound OR phase I metabolite with a functional group via covalent linkage.

Question 36

Most reactions are driven by what?

Answer 36

enzymes

Question 37

CYPs reaction occurs in which phase of metabolism?

Answer 37

Phase 1 metabolism

Question 38

What does inhibition of an enzyme do?

Answer 38

Will keep the enzyme from working properly. Ability to increase amount of parent compound. Leads to toxicity.

Question 39

What does inductions of an enzyme do?

Answer 39

Will enhance the capability of the enzyme. Ability to quickly metabolize the parent compound. Levels dropping faster.

Question 40

Name some CYP inhibitors

Answer 40

amiodarone, Fluconazole, Ketoconazole, SSRIs, methadone

Question 41

Name some CYP inducers

Answer 41

Rifampin, smoking, alcohol

Question 42

What factors affect metabolism?

Answer 42

Genetics - Environmental - diet Disease Factors Age and sex - As we get older, CYP enzymes begin to fail Do not have full set of CYP enzymes until 25

Question 43

In which forms can a medication be eliminated?

Answer 43

Unchanged (parent molecule, metabolite or mixed

Question 44

Is it easier to eliminate polar/hydrophillic compounds or lipophillic compounds

Answer 44

polar/hydrophilic compounds

Question 45

What is the primary excretory organ in the body

Answer 45

the kidneys

Question 46

Glomerular filtrations eliminates

Answer 46

unbound medication

Question 47

Active tubular secretion eliminates

Answer 47

P-gp and other transport proteins

Question 48

Passive tubular reabsorption processes

Answer 48

Weak acids and bases via concentration gradients

Question 49

What is first order kinetics?

Answer 49

As the concentration of the drug in the plasma decreases, less drug is available at the site of metabolism or excretion, and thus as the concentration decreases, the amount being eliminated is also decreasing. Same percentage % always being excreted.

Question 50

What is zero order kinetics?

Answer 50

Seen when the metabolism or excretion processes become saturated. A constant amount or number of drug molecules are eliminated per unit time

Question 51

What is elimination rate?

Answer 51

Fraction or % of the total amount of drug in the body removed per unit of time. This equation can only be done if elimination rate is by first order process.

Question 52

What can cause an increased half life for a med that is eliminated primarily through the liver?

Answer 52

hepatic disorders: cirrhosis, liver failure

Question 53

What is pharmacokinetics?

Answer 53

how drug molecules are handles in the body

Question 54

What are the properties of pharmacokinetics?

Answer 54

Absorption Distribution Metabolism Excretion

Question 55

What factors can effect absorption?

Answer 55

- Dissolution and absorption characteristics - Route - Stability in GI - Metabolism prior to blood stream