Brainscape's Knowledge GenomeTM

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


See full index

Pharmocology > Pharmacokinetics > Flashcards

Pharmacokinetics Flashcards

1
Q

How is the route of drug administration divided?

A

systemic - entire organ is exposed to the drug

local - restricted to one area of the organism

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

How else can the route of administration be divided?

A

enteral - by the GI tract

parenteral - everywhere but the GI tract

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

Advantage and disadvantage of IV drug administration

A
  • rapid onset

- invasive and requires training

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

Advantage and disadvantage of intraperitoneal drug administration

A
  • rich blood supply so good absorption of the drug

- not a very common route and highly invasive

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

List all the routes of drug administration in the body

A
  • dermal
  • intramuscular
  • subcutaneous
  • intraperitoneal
  • intravenous
  • ingestion
  • inhalation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Advantage and disadvantage of dermal administration

A
  • extended release, limit the need to keep on topping up throughout the day
  • tackle malabsorption issues
  • strong dose cannot be administered in this way
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

advantage and disadvantage of inhalation

A
  • drug localised to the target organ so as a result less adverse side effects occur
  • lot of drug loss through the use of aerosol
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

advantage and disadvantage of oral drug

A
  • easy for patients
  • slow release
  • non-invasive
  • inefficient if there is malabsorption
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What two ways do drugs move around the body by?

A
  • bulk flow transfer

- diffusion transfer

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

Describe how the drug enters the blood stream through absorption?

A

The drugs travels to the GI tract where it is absorbed

-it travels to the liver via the hepatic portal system and then enters the systemic circulation

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

How can drugs cross both their aqueous and lipid environments?

A
  • diffuse through the lipids
  • diffuse through an aqueous pore in the lipid
  • carrier molecules
  • pinocytosis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

How do most drugs exist?

A

ionised/ non-ionised

-most are either weak acids or bases

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

Explain what happens to aspirin as it moves from the stomach to the small intestines?

A
  • Aspirin is a weak acid
  • when it is in the stomach, that has a pH lower than itself it is encouraged to be non-ionised
  • it exists the stomach in this form (meaning it can easily cross the lipiud bilayer)
  • when it enters the small intestine, the pH becomes higher and so it becomes ionised
  • it is harder for it to cross the lipid membrane in its ionized form- hence more absorption in the stomach compared to the intestine
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is ion trapping?

A

when part of the ionised drug ends up in the bloodstream but cannot move into tissues because it is in its ionised form - essentially trapping it in the circulation

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

List 4 factors influencing drug distribution

A
  • regional blood flow
  • extracellular binding
  • capillary permeability
  • localisation in tissues
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

How does extracellular binding effect distribution?

A

if a plasma protein is bound then the drug is no longer available for absorption

17
Q

How does regional blood flow effect drug distribution

A
  • well perfused tissue are likely to be exposed to a higher concentration of drug
  • higher metabolically active tissues tend to have a greater blood flow and denser network of capillaries
18
Q

What are the proportions of blood distribution in the body?

A
  • liver 27%
  • kidneys 22%
  • muscles 20%
  • brain 14%
  • heart 4%
19
Q

What % of acidic drugs tend to bind to bind to plasma proteins?

A

50-80%

20
Q

What type of drug can albumin bind to?

A

ionised and non-ionised

21
Q

How does ionised drug pass through the capillaries?

A

-small gaps between endothelial cells are aqueous and so ionised as well for the drug to pass through

22
Q

WHat 3 types of capillary are there?

A

fenestrated- more permeable to drugs
continuous - found in normal vessels and more permeable to drugs
discontinuous- large gaps between endothelial cells

23
Q

How can localisation in tissues affect distribution of the drug?

A
  • fat is not highly perfused, they produce a very high lipophilic environment
  • drugs that are lipophilic tend to localise in fatty tissues
  • fat soluble drugs highly group into fatty tissues e.g. brain and testes
24
Q

What are the 2 major routes of drug excretion?

A
  • kidney

- liver

25
Q

how do the 2 routes deal with drugs?

A
  • kidney converts them into something water soluble

- liver concentrates the drug into bile and then that is excreted into the intestines

26
Q

Which type of drugs tend to be excreted by the liver?

A

larger molecular weight that are very lipophilic

27
Q

What drugs are mostly excreted by the kidneys?

A

xenobiotics

28
Q

How does the drug get into the urine from the kidneys?

A

via active secretion

  • large protein bound complexes cannot be filtered in the glomerulus
  • active secretion of acids and bases in the proximal tubule
  • lipid soluble drugs are reabsorbed in the proximal and distal convoluted tubules
29
Q

How are drugs transported into the bile?

A

active transport- using the same mechanism that transports bile acids and glucuronides

30
Q

What are the other routes of drug excretion? (6)

A
  • lungs
  • skin
  • GI secretions
  • saliva
  • milk
  • genital secretions
31
Q

How can enterohepatic cycling lead to drug problems?

A

the drug is excreted into the gut but then gets reabsorbed back to the liver via enterohepatic circulation
-leads to drug persistence

32
Q

Define bioavailability

A

the proportion of the drug in the body that is available to exert its pharmacological effect

33
Q

Define apparent volume of distribution

A

the volume in which the drug appears to be distributed

34
Q

Define biological half life

A

the time taken for the concentration of a drug to fall to half of its original value

35
Q

Define clearance

A

the volume of blood cleared of a drug in a unit time

Pharmocology (16 decks)

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