pharmacology intro

Question 1

What does rate of filtration depend on

Answer 1

Extend of plasma protein binding

Question 2

How can the solubility of a drug be described?

Answer 2

Limited

Question 3

How do drugs leave the circulation

Answer 3

filtration through capillaries

Question 4

What does amphipathic mean?

Answer 4

Having both hydophillic and hydrophobic parts

Question 5

What are mostly amohipathic

Answer 5

Proteins

Question 6

What are lipophilic compounds attracted to?

What happens when they attract?

Answer 6

They are attracted to lipophiloc grounds and become loosely bound to protein molecule

Question 7

How long do drugs bind for

Answer 7

They bind temporarily

Question 8

What is there an equalibrium between

Answer 8

Bound and free drugs

Question 9

What do drugs mostly bind to

Answer 9

Mostly to albumin

Then: globulins, glycoproteins and lipoproteins

Question 10

Do proteins leave the bloodstream

Answer 10

No

Question 11

What drugs pass into other compartments and how?

Answer 11

Non-bound drugs bind to cellular receptors, pass across the membrane into other compartments

Question 12

What drugs can be distributed, metabolised and excreted ?

Answer 12

Only non-bound drugs

Question 13

What happens if a free drug leaves the bloodstream

Answer 13

More free drug will be released from the protein to maintain the equilibrium

Question 14

What prolongs the time a drug is in the plasma?

Answer 14

Strong protein binding

Question 15

How many drugs compete for binding sites? Why is this important
Give an example

Answer 15

2 - this is important when giving more than one drug - eg warfarin and asprin

Question 16

What are the body fluid compartments?

Answer 16

Plasma, extracellular fluid, intercellular fluid, fat

Question 17

What does distribution between compartments depend on?

Answer 17

Permeability across barriers
PH of compartments
Binding capacity
Fat solubility of drug

Question 18

What does the blood brain barrier consist of

Answer 18

Continuous layer of endothelial cells- joined by tight junctions

Question 19

How do drugs pass into the brain

Answer 19

The brain is inaccessible to many drugs.

Hugh lipid solubility is needed

Question 20

What happens when there is inflammation in the brain

Answer 20

Disrupted integrity - can use penicillin in bacterial meningitis

Question 21

Where is the blood brain barrier weak?

Answer 21

It is leaky in zones CTZ

Question 22

What barriers are there in the body

Answer 22

Placental barrier

Blood brain barrier

Question 23

How is the placenta barrier

Answer 23

Not very efficient.

Most drugs cross