Pharmacokinetics

Question 1

What does enteral administration mean?

Answer 1

Using the GI tract (oral, sublingual, buccal, rectal)

Question 2

What does parenteral mean?

Answer 2

Non-GI delivery

IV, IM, SQ, intrathecal, epidural

Question 3

What route of administration get the greatest level of compliance?

Answer 3

Enteral

Question 4

What is the problem with using the GI tract for administering drugs?

Answer 4

Digests the drugs

Question 5

What is buccal administration? What is the advantage of using this route, as compared to other enteral routes?

Answer 5

Placing drug between tongue and cheek

Bypasses the liver

Question 6

What are the two major disadvantage of parenteral administration of a drug?

Answer 6

Pierce the skin, lowers compliance

No way to reclaim drug

Question 7

Which route of administration gives the highest bioavailability?

Answer 7

Parenteral (IV)

Question 8

What is the general type of chemical that is absorbed across the buccal mucosa?

Answer 8

Lipid soluble

Question 9

What percent of a drug that is given rectally bypasses the liver?

Answer 9

~50%

Question 10

What can significantly impact the absorption of a drug administered IM?

Answer 10

Exercise/fat distribution

Question 11

What is the specific advantage of SQ administration of a drug?

Answer 11

Constant rate of absorption over a long period of time

Question 12

What is intrathecal administration of a drug?

Answer 12

Injection into the subarachnoid space

Question 13

What is transdermal administration?

Answer 13

Think patches

Question 14

Lipophilic, or hydrophilic drugs are more likely to be successful with paradermal route of administration

Answer 14

Lipophilic

Question 15

What type of drug side effects should cause concern for giving them via inhalation?

Answer 15

Anything that upsets the heart

Question 16

What is the charged form of a weak base: protonated or unprotonated?

Answer 16

protonated

Question 17

What is the charged form of a weak acid: protonated or unprotonated?

Answer 17

Unprotonated

Question 18

Which can pass through a lipid bilayer more easily: charged or uncharged substances?

Answer 18

Uncharged

Question 19

How can the henderson-hasselbach equation be used in pharmacokinetics?

Answer 19

check protonated form in relation to the pH of a given solution

Question 20

What is the pKa?

Answer 20

pH at which [protonated form] = [unprotonated form]

Question 21

Weak acids are more likely to be absorbed where?

Answer 21

stomach d/t low pH

Question 22

Weak bases are more likely to be absorbed where?

Answer 22

Intestines

Question 23

What are the four major factors of drug distribution?

Answer 23

1. Cardiovascular factors
2. Tissue binding
3. Drug molecule size
4. Lipid solubility

Question 24

What is the technical definition of drug distribution?

Answer 24

The process by which a drug leaves the circulation and enters the tissues perfused by the blood

Question 25

What is the role of proteins in the blood and drug distribution?

Answer 25

Drugs can bind to proteins, leaving less available to distribute

Question 26

What is phase I of biotransformation?

Answer 26

Generate a more polar molecule by exposing a functional group on the parent compound.

Question 27

What is phase II of biotransformation?

Answer 27

Reactions yielding a more water soluble conjugated product to be excreted

Question 28

What is the rate limiting step in biotransformation?

Answer 28

p450 enzymes in the ER

Question 29

Where are the products of phase II of biotransformation excreted?

Answer 29

Bile canaliculi

Question 30

Do all drugs go through phase I and II biotransformation?

Answer 30

no

Question 31

What are the three most common reactions done in phase II?

Answer 31

Glucuronidation Sulfation Acetylation

Question 32

What is the role of UDP?

Answer 32

Conjugates metabolites to be excreted

Question 33

What is the "first pass" effect?

Answer 33

Drug absorbed by the stomach or intestines will initially be carried to the liver by the portal vein

Question 34

What are the three major factors that determine the renal excretion?

Answer 34

GFR Plasma protein binding pH of urine

Question 35

How are most drug metabolites excreted into feces? (2)

Answer 35

Bile | Hepatocytes secrete directly into GI tract

Question 36

What is the volume distribution?

Answer 36

The measure of space in the body available to contain a drug

Question 37

What is clearance?

Answer 37

Measure of the ability of the body to eliminate a drug

Question 38

What are the two major factors that determine the amount of drug within the body?

Answer 38

Distribution and elimination