Basic Pharmacokinetics

Question 1

What does PK data allow?

Answer 1

To calculate correct dose

Question 2

What is DL?

Answer 2

Initial dose

Question 3

What is Cmax?

Answer 3

Max plasma conc

Question 4

What is Tmax?

Answer 4

Time to reach Cmax

Question 5

What is VD?

Answer 5

Distribution vol

Question 6

What is C?

Answer 6

Plasma conc

Question 7

How do you calculate DL?

Answer 7

V X C

Question 8

What does PK give us?

Answer 8

Which dose to give
Which administration route
How often to give dose
Which administration formulation

Question 9

What are the different administration routes?

Answer 9

Oral
Parental
Nasal
Topical
Rectal
Vaginal

Question 10

Describe systemic

Answer 10

Uses circulatory system to distribute drug
Whole body exposed
Greater risk of side effects

Question 11

Describe topical

Answer 11

Drug applied to specific part of body
Only small areas of body exposed to drug
Adverse effects are local

Question 12

Describe channel protein

Answer 12

Forms pores in membrane

Small molecules can pass through adjacent cells connected at tight junctions

Question 13

Describe carrier protein

Answer 13

Bind specific drugs

As consequence undergo conformational change = molecules pass through

Question 14

What is therapeutic range?

Answer 14

Range of plasma conc of drug, which therapeutic effect is achieved, which is safe + doesn’t cause major side effects

Question 15

What is narrow therapeutic range?

Answer 15

Very short range of drug serum conc at which drug has therapeutic effect = drug can be easily over/under dosed

Question 16

Describe ionic drug binding

Answer 16

Association of ions of opposite charge by transfer of e-

Question 17

What does it mean in ionic drug binding that they are weak?

Answer 17

Easily broken through induction of different ion with greater affinity

Question 18

Describe hydrogen drug binding

Answer 18

Strongest bound

Question 19

What does hydrogen bound determine?

Answer 19

The way the drug interacts with target molecule

Degree of binding to plasma protein

Question 20

What is different about hydrogen bound drugs?

Answer 20

Binding is reversible, conc dependent + subject to competition with other drugs

Question 21

Describe continuous capillary bed

Answer 21

In almost all vascularised tissues
Complete endothelial lining with tight junctions
NOT associated with brain

Question 22

Describe fenestrated capillary bed

Answer 22

Has pores

Permeable to larger molecules

Question 23

Where is fenestrated capillary bed common?

Answer 23

Small intestine + kidney

Question 24

Describe sinusoid capillary bed

Answer 24

Intracellular gaps + incomplete basement membrane
Intracellular clefts + fenestrations
Passage of large molecules

Question 25

Which is the least common capillary bed?

Answer 25

Sinusoid

Question 26

Describe blood flow in sinusoid capillary bed

Answer 26

Very slow = more time for drug exchange

Question 27

Where is sinusoid capillary bed?

Answer 27

Liver, spleen, bone marrow, lymph nodes + endocrine glands

Question 28

Describe blood brain barrier structure

Answer 28

Continuous non-fenestrated vessels

Specialised layer of tightly packed capillary endothelial + glia cells

Question 29

What is function of BBB?

Answer 29

Protect CNS from toxins

Provides obstacle for drug delivery

Question 30

What is problem with BBB?

Answer 30

Inflammation can make BBB more permeable

= bacterial meningitis, penicillin can penetrate through inflammation