Drug Absorption Flashcards

1
Q

Four basic factors that determine drug pharmakinetics

A

Absorption
Distribution
Metabolism
Elimination

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

Define absorption

A

The process of movement of uncharged drug from site of administration to the systemic circulation

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

How quickly the drug will get into the system at a sufficient amount

A

Tmax

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

Maximum concentration achieved (peak concentration)

A

Cmax

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

All the amount of drug that has gone into systemic circulation

A

Area Under Curve (AUC)

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

A drug given IV has _____ Bio-availability

A

100%

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

The amount of drug in circulation

A

Bioavailability

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

Factors that effect bioavailability

A

Formulation
Ability of drug to pass physiological barriers
Gastrointestinal effects
First pass metabolism

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

First Pass Metabolism

A

Drugs that are absorbed via the GIT are circulated to the liver first via the hepatic portal vein
The liver acts as a filter and only part of the drug is circulated systemically

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

A physiological barrier

A

Transport membranes

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

Actions across transport membranes

A
Passive diffusion
Filtration
Bulk flow
Active transport
Facilitated diffusion
Ion-pair transport
Endocytosis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Most drugs completely ionise in water (True or False)

A

False

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

Only non-ionised (non-polar) drugs diffuse across the membrane (True or False)

A

True

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

Most drugs are not weak acids or bases (True/False)

A

False

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

Does the degree of ionisation depend on the PH of the environment as well as the drug

A

Yes

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

An acidic drug concentrated in the compartment with High ph (alkali)

A

Ion-trapping

17
Q

Henderson-Hasselbalch equation

A

The relationship between the local PH and the degree of ionisation

18
Q

The more positive the value of Pka is the smaller the extent of dissociation

A

True

19
Q

The ability of a drug to diffuse across a lipid barrier

A

Lipid-water partition coefficient

20
Q

Facilitated diffusion (5)

A
Along conc. gradient
Requires carriers
Saturable
Mixed order kinetics
Monosaccharides, amino acids and vitamins
21
Q

Other routes of drug administration

A
Subcutaneous/intramuscular
Sublingual, buccal
Rectal
Inhalation/Nasal
Transdermal
22
Q

Taking a higher does will increase the ______ but not the ________

A

Cmax and Tmax

23
Q

Therapeutic index

A

The relationship between the doses of a drug that causes lethal or toxic effects with the dose that causes therapeutic effects

24
Q

Therapeutic Range

A

Above this range the drug is not effective