Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Pharmacology: Exam 1 > Unit 1. Lec 1: Pharmacokinectics > Flashcards

Unit 1. Lec 1: Pharmacokinectics Flashcards

1
Q

Define Pharmacokinetics

A

Study of absorption, distrubition and elimination of drugs and other substances

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

What is the affect of drugs on illnesses?

A

They do not cure the illness, they just mask the symptoms

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

True or False: All drugs at high enough concentrations are poisonous

A

True

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

What determines the poisonious level of a drug/substance?

A

Dosage

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

Absorption

A

The process by which the drugs enter the systemic circulation

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

What is the only way to bypass absorption

A

Through IV

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

What other ways can drugs enter systemic circulation?

A
  • Oral–>GI system–>systemic blood
  • Skin (super lipophilic)–>systemic blood
  • Inhalent (Lungs)–>systemic blood
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

True of False: Drugs taken by the hepatic vein are absorbed

Provide explanation

A

False; b/c they have not entered the systemic circulation

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

Distribution

A

The phenomenon by which drugs reach its site of action. (To target receptor)

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

Elimination

A

The process by which the drugs are enzymatically altered (biotransformation) mainly in the liver and eventually excreted by the kidneys.

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

What must occur for the absorption, distribution and elimination of drugs?

A

The drug must cross the cell membrane

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

How well a drug can cross the cell membrane is correlated with?

A

their physiological characteristics

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

List the factors that determine the transfer of drugs across membranes

A
  1. Molecular size and shape of drug
  2. Solubility of drug (lipid:water partition coefficient)
  3. Most drugs are weak acids or weak bases
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What types of drugs can cross the blood brain barrier (BBB)?

A

Highly lipid soluble

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

What types of drugs cannot cross the BBB?

A

Water soluble

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

What is the lipid:water partition coefficient explaining?

A

How lipid soluble a drug is

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

Weak acids…..
Weak bases…..

A
  • Weak acids give H+ ion
  • Weak bases take H+ ion
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Nonionized drugs ____ cross the cell membrane. Ionized drugs ____ cross

A

can, cannot

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

What is a nonionized vs ionized ion?

A
  • Nonionized=no charge
  • Ionized=charged
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

You add 1 g of a drug, 1 g of water and 1 g of oil in a separatory funnel and mix it. You remove the water and measure 0.1 g of the drug in the water and 0.9 g of the drug in the oil. What is the lipid:partition coefficient?

A

0.9/0.1 or 9 making the drug lipophilic

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

The degree of ionization depends on what?

A

pH

22
Q

What is pka

A

50% of ionization; pH=pka

23
Q

When the pH is low (more acidic), weak acid is

A

More unionized

24
Q

When the pH is high (more basic) ,weak acids are

A

More ionized

25
Q

When the pH is low (more acidic), weak bases are

A

more ionized

26
Q

When the pH is high (more basic), the weak bases are

A

more unionized

27
Q

What is the Henderson-Hasselbalch Equation

A

Allows for the calculation of the degree of ionzation for weak acids or weak bases

28
Q

What is the Henderson Hasselbalch equation for a weak acid

I owe U

A

pH=pka +log10(I/U)

I=ionized
U=unionized

29
Q

What is the Henderson Hasselbalch equation for weak bases

U are Basic, U over I

A

pH=pka+log10(U/I)

I=Ionized
U=Unionized

30
Q

List pH of selected body fluids

A
  • Gastric juice:1.0-3.0
  • Small intestine (duodenum): 5.0-6.0
  • Small intestine (ileum): 8.0
  • Large Intestine: 8.0
  • Plasma: 7.4
  • Cerebrospinal fluid: 7.3
  • Urine: 4.0-8.0
31
Q

Term for when drugs become trapped on one side of a lipid mucosal barrier due to change of pH

A

Ion trapping

32
Q

Weak acids get trapped on what side?

A

Basic

33
Q

List the processes (5) of drug transfer

A
  • Passive Diffusion
  • Active Transport (Carrier-mediated process)
  • Facilitated Diffusion ( Carrier-mediated process)
  • Bulk Flow
  • Pinocytosis
34
Q

What is the most common form of drug transfer?

A

Passive diffusion

35
Q

Passive diffusion:
1. movement on gradient?
2. saturable?
3. carrier mediated?
4. example

A
  1. Moves only DOWN the [ ] gradient
  2. NOT saturable
  3. NOT carrier-mediated
  4. ethanol (alcohol)
36
Q

Active transport:
1. movement on gradient?
2. saturable?
3. carrier mediated?
4. Energy?
5. examples

A
  1. Can move up and down [ ] gradient
  2. Can be saturated (limited carrier proteins)
  3. Requires a carrier
  4. Needs ATP
  5. Pencilin in kindneys, p-gylcoprotein, and MRP
37
Q

What are xenobiotics?

A

Foreign chemical substance that goes through active transport

38
Q

Faciliated diffusion:
1. movement on gradient?
2. saturable?
3. carrier mediated?
4. example

A
  1. Moves only DOWN the [ ] gradient
  2. Can be saturated
  3. Involves a carrier (no energy needed)
  4. amino acids transport into the brain
39
Q

What does fixed capacity mean?

A

You reach vmax so you cant go higher than that

40
Q

Describe bulk flow

A
  • Movement of free molecules through the capillary junctions

Only free drugs can move through the fenestrations (holes) b/n capillaries, but most drugs are bound to plasma proteins (Not with BBB)

41
Q

Describe Pinocytosis

A

Formation and movement of vesicles

Plays a minor role in drug transport

42
Q

List the factors (5) that influence drug absorption

A
  1. Solubility
  2. Concentration
  3. Circulation
  4. Surface area
  5. Time
43
Q

How does Solubility affect drug absorption?

A
  • Aqueous vs oily solution
  • Higher Lipid H2O coeffient means drugs absorb better
  • pH (ex. aspirin coat)
44
Q

How does concentration affect drug absorption

A

High [ ] of drug absorbs more rapidly

45
Q

How does circulation affect drug absorption?

A
  • Higher circulation, Higher absorption (e.g. local massage, heat application)
  • Lower circulation, Lower absorption (e.g. state of shock, disease state)
46
Q

How does surface area affect drug absorption?

A
  • Increase surface area, increase absorption
  • e.g. Intestinal muscosa (oral meds), pulmonary alveolar epithelium (gases like anesthia), skin (patches, pesticides)
47
Q

How does time affect drug absorption?

A
  • Shorter time (present of drug), faster absorption
  • Longer time (presence of drug), slower absorption
48
Q

Which of the following bypasses absorption?
a. PO
b. Topically
c. Intravenous
d. Inhalation

A

c. Intravenous

PO–>Goes through first pass effect

49
Q
  1. Which of the following processes has the potential issue of becoming saturated?
    a. Passive transport
    b. Active transport
    c. Facilitated diffusion
    d. B and C
A

d. B and C

Facilited diffusion has NO transporters

50
Q
  1. Which of the following is the correct equation for calculating the degree of ionization of a week base?
    a. pH = pKa + log U/I
    b. pH = pKa + log I/U
    c. pKa = pH + log U/I
    d. pKa = pH + log I/U
A

a. pH=pKa+logU/I

b. pH=pKa + logI/U (Weak Acid)

51
Q
  1. Which of the following is not an influence on drug absorption?
    a. Bulk Flow
    b. Solubility
    c. Concentration
    d. Circulation
A

a. Bulk Flow (process of drug transfer)

Pharmacology: Exam 1 (9 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions