Applying PD/PK theory to depressants

Question 1

How to calculate amount of alcohol

Answer 1

ABV x 0.78 x volume consumed per 100ml

Question 2

lipid solubility of 9-tetrahydrocannabinol

Answer 2

> 6000, it has one compound which is lipid soluble

Question 3

For inhaling drugs, only 50% of administered dose gets deep enough into the lungs to allow absorption, where do the remaining 50% goes to

Answer 3

swallowed or breathed out

Question 4

Why should we drink alcohol on full stomach

Answer 4

slows down stomach emptying by alcohol and takes time to digest and break down solid food, alcohol will retain in stomach

Question 5

Compare the plasma protein binding ability between alcohol and cannabis and elimination rate

Answer 5

cannabis highly bound to plasma proteins (90%) while ethanol does not bind very effectively (10%) , this makes alcohol to eliminate faster than cannabis

Question 6

what does the tissue localisation of alcohol depends on

Answer 6

Alcohol has a very low octanol:water partition coefficient which means it is soluble in water and will be preferentially distributed to tissues which have a higher water content,
When alcohol concentration is high in the blood, there will be a drive to push alcohol molecules into the brain until an equilibrium is reache

Question 7

What does the tissue localisation of cannbis depends on

Answer 7

high octanol:water partition coefficient -> found at a greater concentration in the brain than in the blood at equilibrium. It will also accumulate in the adipose tissue, as expected, due to its high lipid solubility

Question 8

Are obese man more sensitive to alcohol or cannabis and non obese?

Answer 8

alcohol, less body water so alcohol is more concentrated producing a more powerful effect; cannabis, more body fat absorbing a greater % of cannabis and less cannabis available to produce effect

Question 9

what is the action of alcohol dehydrogenase

Answer 9

responsible for 75% of hepatic metabolism of ehtanol to acetaldehyde, remaining by P450 enzymes

Question 10

what is the action of aldehyde dehydrogenase

Answer 10

convert acetaldehyde to acetic acid

Question 11

11OH-THC is more or less potent than 9-THC

Answer 11

more potent

Question 12

what led to the depressant effect of cannabis

Answer 12

cannabis binding to cannabinoid receptor reduces adenylate cyclase activity causing a depressant effect

Question 13

How can alcohol lead to depressant effect

Answer 13

loosely bind to binding site of opioid receptor, leading to increase of GABA receptor activity, but decreased activity of NMDA receptor and Ca2+ channels

Question 14

How do cannabis impair memory formation, and can alcohol do the same

Answer 14

activation of cannabinoid receptors on mitochondria within dentate gyrus; alcohol lacks sensitivity causing difficulty in identifying the specific target that mediates this response

Question 15

Toxic effects of alcohol

Answer 15

respiratory depression, liver damage by NAD+ cofactors reducing b-oxidation of fats, P450 up-regulated causing oxidative stress and mitochondrial damage, acetyladehyde decrease activity of important enzymes causing hepatocyte cell death and hepatitis

Question 16

toxic effects of cannabis

Answer 16

psychosis, affecting anterior cingulate cortex

Question 17

How do you calculate units of alcohol

Answer 17

% ABV x volume /1000

Question 18

How does excess alcohol intake impair β-oxidation of fatty acids?

Answer 18

Causes an increased NADH/NAD ratio

Question 19

The following diagram shows the common phase 1 and phase 2
metabolic reactions. Which of these reactions occur in both alcohol
and cannabis metabolism?

Answer 19

oxidation

Question 20

Which of the pharmacokinetic factors, that vary depending on the
route of drug administration, will be lower if an individual drinks
alcohol on a full stomach compared with drinking alcohol on an
empty stomach?

Answer 20

bioavailability, slowing bioavailability into the bloodstream