Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Pharmacology-Au15 > Absorption, Distribution, and Fate of Drugs. Exam 1 > Flashcards

Absorption, Distribution, and Fate of Drugs. Exam 1 Flashcards

(62 cards)

Start Studying
1
Q

What are the sites of absorption for oral drugs?

A

Stomach and small intestine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is the pH of the stomach?

A

1.4

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is the pH of the small intestine?

A

3.0-7.0

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

How are oral drugs absorbed?

A

drugs enter from the lumen, through endothelial cell membranes, and into the bloodstream

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What are the four basic steps of a drugs life in your body?

A

absorption, distribution, metabolism, excretion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

_______ molecules can cross down a concentration gradient (passive diffusion) through the membrane.

A

Lipophilic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

_______ is the ratio of the compound’s concentration in a known volume of n-octanol to its concentration in a known volume of water after the octanol and water have reached equilibrium

A

Partition Coefficient

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

The _______ the partition coeffcient, the more likely a drug will be absorbed by passive diffusion. Why?

A

larger

passive diffusion occurs with lipoPHILIC molecules and PC is essentially a ratio comparing concentration in oil to water

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

_______ molecules are more likely to be absorbed by passive diffusion.

A

Smaller

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

More _______ moieties will make a compound more soluble in water and ______ likely to cross a membrane by passive diffusion.

A

polar

less

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Why is pH important when considering absorption of drugs?

A

pH of drugs that are acidic or basic will dramatically affect the location at which it is absorbed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Aspirin has a pKa of 3.4 and will be absorbed in the ______.

A

Stomach

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Codeine has a pKa of 8.1 and will be absorbed in the ______.

A

small intestine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

A lower pKa indicates that the drug will be absorbed in a more _______ environment.

A

acidic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

A higher (more positive) pKa indicates that the drug is more ______ and will be absorbed in a similar environment such as the _______.

A

basic

small intestine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Facilitated diffusion across a cell membrane utilitzes ________ or carrier proteins.

A

protein channels

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What are the three methods of diffusion that are used by drugs?

A

Passive, Facilitated, Active Transport

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

_____ transporters are active transporters that use ATP to kick drugs out of cells.

A

ABC

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

____ transporters exchange Na+ for K+ to transport drugs that are organic acids or bases.

A

SLC

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What are the two transporter types used to actively transport drugs?

A

ABC and SLC

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

True or False: SLC Transporters exchange Cl and K to move organic drugs.

A

False: exchange of Na and K

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Name five factors that affect oral absorption of drugs.

A
  1. pH
  2. Surface area
  3. Gastric emptying
  4. Dosage Form
  5. Drug inactivation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

How does surface area affect oral absorption of drugs?

A 
Greater surface area = more time
Small intestine (6-8 hrs) > stomach (30min-4hrs)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What administration instructions would reflect gastric emptying properties?

A

“take with food”

if a drug needs to pass more quickly, it should be taken on an empty stomach. if a drug needs lipid transport, it should be taken with food

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Slow Release Tablet is an example of ________ and the variations exist due to presence or absence of _______.
dosage form | surface proteins
26
Other than orally, what are five additional methods for drugs administration?
1. Inhalation (asthma, COPD) 2. Intravenous 3. Intramuscular (gaps in endothelium) 4. Subcutaneous 5. Topical
27
Greater amount of blood getting to the tissue, known as increased ________, will increase the amount of drug entrance.
profussion
28
Lipophilic drugs are fast; whereas, water soluble drugs must pass through _______ and are much slower.
endothelial gaps
29
Similar to absorption from the lumen, drugs may enter cells from the ________.
interstitial fluid
30
Name a critical location where drug distribution is restricted.
CNS-blood brain barrier
31
What is the volume of distribution?
an indication of how a drug is distributed, based on how much is in the plasma and how much was added. Vd = Q/C Vd = amt. administered/ concentration at equilibrium
32
An average person contains 41 total liters: ____ liters of plasma, ____ liters of interstitial space, and _____ liters of cells.
3 plasma 9 space 29 cells
33
If a drug is _____ soluble, you can administer the drug, measure concentration in plasma, and calculate the Vd to get an idea where it is distributing.
Water
34
If a drug goes to plasma and interstitial space, but not into cells, the Vd would = ______
12 liters
35
If a drug goes only to plasma, the Vd would =______
3 liters
36
If a drug goes to cells but not plasma or interstitial space, the Vd would =_______.
29 liters
37
If a drug distributes everywhere, such as urea, what would its volume of distribution be?
41 liters
38
What are the phases of drug metabolism?
phase I: Add/Uncover functional group, make it polar phase II: Conjugation, link something to it phase III: processed and pumped out of cells
39
Where does most drug metabolism take place?
liver
40
What are microsomes?
membrane bound enzymes that metabolize drugs
41
Where do microsomes bind?
smooth ER of hepatocytes
42
Phase I reactions can be broadly grouped into what three categories?
Oxidations Reductions Hydrolysis
43
What is the most important of the phase 1 oxidation systems?
P450 enzymes
44
Cytochrome ____ enzymes catalyze the oxidative metabolism of xenobiotics, the initial step in the biotransformation and elimination of a wide variety of drugs and environmental pollutants
P450
45
Where are cytochrom P450 enzymes found?
smooth ER of liver cells
46
Reductions most commonly occur in _________.
enteric bacteria
47
Drug hydrolysis involves splitting of ____ or ____ to yield an acid and an alcohol.
esters | amides
48
__________ metabolism occurs in the liver and other tissues when a drug mimics a natural substance.
Non-microsomal
49
What are six factors that will affect drug metabolism?
1. Entry to liver 2. Enzyme inhibition 3. Enzyme induction 4. Genetics 5. Age 6. Pathology
50
When metabolizing drugs, there are two rates k1 and k2. k1 is the movement to the liver, k2 is the metabolism. Which rate is typically limiting (slower)?
k1 (movement to the liver) is typically slow
51
Protein binding will ______ drug metabolism.
slow down
52
Transporters will ______ drug metabolism.
speed up
53
Where are drugs typically excreted?
the kidney
54
What are the three components of the kidney filtration?
glomerular filtration tubular reabsorption active transport
55
A major area of filtration within the glomeruli occurs at ________.
The basement membrane
56
The glomerulus sits within _________.
Bowmans Capsule
57
Tubular reabsorption includes passive transport of _____, active transport of _____, and ____ via osmosis.
Cl- Na+ water
58
True or False: Some compounds are actively pushed out from the capillary endothelium into the urine.
True
59
What does half-life of a drug measure?
the speed at which half of the drug has cleared
60
How many half-lives must occur in order to have only 6% of drug remaining?
four | 50, 25, 12, 6
61
If you have two drugs and neither is reabsorbed. Drug 1 is filtered, Drug 2 is actively secreted. Which drug will clear faster?
Drug 2
62
Aspirin is absorbed in the stomach where pH is low. If pH is increased, what will happen?
more aspirin will be ionized and it will be less likely to be absorbed out of the blood or reabsorbed by the kidney

Pharmacology-Au15 (4 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions