Lecture 13 - Enzymes and Alcohol

Question 1

Why are enzymes important in pharmacology?

Answer 1

Drug metabolism

Drug targets

Question 2

Drug metabolism

Answer 2

– Enzymes remove drugs from body

– Changes their activity can
change individual drug
responses

Question 3

Drug Metabolism: Alcohol (Ethanol)

Slow process

Answer 3

Alcohol Dehydrogenase (ADH)
Acetaldehyde (Aldehyde)
Aldehyde Dehydrogenase
Acetic Acid

Question 4

Between Ethanol and Allyl alcohol will the enzyme metabolizes first preferentially?

Ethanol kM = 0.45
Allyl kM = 3.0

Answer 4

Ethanol

Low kM
High O affinity

Question 5

Ethylene Glycol metabolism and toxicity

Answer 5

Alcohol dehydrogenase (ADH)
Glycolaldehyde (Aldehyde)
Aldehyde dehydrogenase (ALDH)
Glycolic acid (Glycolate)
Glyoxylic acid
Oxalic Acid (toxic)

Question 6

The process to get rid of ethylene glycol makes it

Answer 6

More poisonous

To make the patient better need to prevent the pathway

Question 7

How do you prevent the pathway of ethylene glycol from happening?

Answer 7

Give alcohol ethanol

Prevent Alcohol dehydrogenase and Aldehyde dehydrogenase

Question 8

Poison info centre if patient took too much ethylene glycol threshold INTERVENTION LEVEL

Answer 8

Symptoms
Drowsiness
Mild irritation
Exposure to self harm

Question 9

Poison info centre if patient took too much ethylene glycol TREATMENT

Answer 9

Ethanol
Fomepizole (inhibitor of Alcohol dehydrogenase)
Approved treatment for antifreeze poisoning

Question 10

How do drugs act?

Answer 10

Go in body
Bind (enzymes, Receptors)
Change process
Change physiology

Question 11

Receptors 4 types

Answer 11

Forms channel across membrane (K pumps, Na pumps, Ca pumps)

Transmit signal across membrane (Choline receptor)

Membrane bound enzymes

Intracellular.

Question 12

Receptors come in lots of

Answer 12

shapes and sizes

Question 13

Enzyme

Answer 13

1 active site

Change S to P

Bind S

Question 14

Receptor

Answer 14

Multiple bind sites

Unchange

Bind ligands

protein molecule that receives chemical signals from outside a cell

Question 15

Enzyme Terminology

Answer 15

Substrate

Inhibitor

Question 16

Receptor Terminology

Answer 16

Ligand
Agonist
Antagonist

Question 17

Ligand

Answer 17

Molecule / drug that binds to receptor

Question 18

Agonist

Answer 18

Binds to receptor as something changes

A chemical capable of activating a receptor to induce a response

Increase action of receptor

Question 19

Antagonist

Answer 19

A drug blocks receptor and stops the effects of another drug or molecule

Question 20

What is an agonist at GABAa receptor?

Answer 20

Alcohol

Question 21

GABAA Receptor

Answer 21

Multiple binding sites
Membrane bound
Ligand gated Cl- channel

Question 22

GABAA receptor main effects

Answer 22

Inhibitory

Turns down responses to other stimuli

Question 23

GABAA Ligands (many things that bind)

Answer 23

Ethanol (Alcohol)
Benzodiazepines (sedatives)
Barbiturates (seadtives)

Question 24

When ligand binds conformation changes and allows

Answer 24

Cl- ions

Question 25

Alcohol and GABAA

Answer 25

Agonist binding opens Cl- channels allows Cl- into cell

Decrease activity in brain
Loss coordination, memory loss, slurred speech etc.

Question 26

Effects of Alcohol and GABAA depends on

Answer 26

dose

Question 27

Lower dose of Alcohol and GABAA

Answer 27

Loss inhibitions and relaxation

Question 28

High dose of Alcohol and GABAA

Answer 28

Coma or death

Question 29

The enzymes in alcohol dehydrogenase.

Answer 29

In dehydrogenase can’t process alcohol quick enough
Alcohol builds up
More Cl- ions in cell
Leads to death

Question 30

In the case study our patient showed slurred speech, drowsiness and
eventually became unresponsive. How can you account for these
symptoms?

Answer 30

thylene glycol binds to GABAA receptor and causes similar symptoms as Alcohol.