Alcohol

Question 1

Disulfram or ANTABUSE is administed to alcoholics when? What are its intended effects?

Answer 1

It affects alcohol dehydrogenase in order to cause high levels of acetylaldehyde, producing symptoms associated with hangover. Alcohol + Disulfram produces:

Dizziness, sweating, emesis, respiration difficulties, nausea, orthostatic hypotension.

Question 2

Are chronic alcoholics more or less sensitive to barbituates? Why?

Answer 2

Less sensitive to barbituates.

Because they have a higher rate of oxidative metabolism, and because barbitutates and alcohol make use of the same pathways, barbituates are processed more easily by a chronic alcoholic.

Question 3

What is the characteristic response to alcohol?

Answer 3

Euphoria, impaired thought process and decreased motor control.

Question 4

Alcohol is:

1. An agonist of the ______ receptor
2. An antagonist of the ______ receptor
3. Activates the release of _______ and ________

Answer 4

1. An agonist of the GABA receptor
2. An antagonist of the NMDA receptor
3. Activates the release of serotonin and dopamine

Question 5

Why does alcohol cause vasodilation?

Answer 5

Due to central vasomotor depression. This leads to decreased innervation of smooth muscle, leading to vasodilation.

Question 6

Peak levels of plasma alcohol concentration occurs how long after consumption?

Answer 6

30 to 90 minutes.

Question 7

What other drugs also have the same effect as Disulfram?

Answer 7

Cephalosporins and sulphonylurea.

Sulphonylurea are a group of anti-diabetic drugs have the same effect.

Question 8

The accumulation of acetylaldehyde in the body leads to whcih four symptoms?

Answer 8

1. Headache
2. Nausea
3. Gastritis
4. Dizziness

Question 9

Early on, alcohol impairs thought and motor processes dependent on:

Answer 9

Judgement, training and previous experience.

Question 10

True or false, acetylaldehyde is the final metabolic product of alcohol.

Answer 10

False. The final metabolic byproduct of alcohol is acetic acid.

Question 11

Alcoholics gaining the majority of their calories from alcohol results in a deficiency in _______?

Answer 11

Thiamine.

Question 12

Why does alcohol abuse cause hepatitis?

Answer 12

1. Increased fat accumulation in the liver.
2. Increased fatty acid release from fat cells.
3. Decreased fatty acid oxidation.

Question 13

Which stage of alcohol withdrawal has a high rate of mortality? How long is this after the last drink?

Answer 13

Stage III, “Delirium Tremens”.

It occurs 72-96hrs after the last drink.

Question 14

How significant is the rate of excretion of alcohol to plasma concentration changes?

Answer 14

Not very significant. Most alcohol is metabolised.

Question 15

What anti-psychotics are commonly used in the treatment of alcohol withdrawal?

Answer 15

Haloperidol.

Droperidol.

Question 16

Will the use of diuretics assist in lowering BAC? Why or why not?

Answer 16

No.

Alcohol is mostly metabolised, not excreted. So increasing the rate of excretion will not lead to a lower plasma concentration.

Question 17

Thiamine is also known as? It is commonly deficient in which syndrome?

Answer 17

Thiamine is also known as Vitamin B1. It is commonly deficient in Wernicke-Korsakoff syndrome.

Question 18

Explain the cellular mechanisms of tolerance to alcohol.

Answer 18

1. More Ca2+ channels - leading to more vesicle release, less depressant effect in the brain.
2. Increased NMDA receptors - more likely to have stimulation, meaning depressants have less signal.
3. Decreased GABA receptors - less chance of binding to GABA and causing depressant effects.

Question 19

Explain how the concentration of alcohol consumed affects pharmacokinetics.

Answer 19

A higher concentration will cause increased gastric irritation.

Gastric irritation leads to mucosal secretion and decreased gastric emptying.

Decreased gastric emptying means the alcohol dehydrogenase in the stomach has a longer time to act on the ingested alcohol before it gets to the bloodstream. Meaning less alcohol gets to the plasma than was delivered to the stomach.

Question 20

Why are benzodiazepines used in the Rx of alcohol withdrawal?

Answer 20

The increase the effect of GABA receptors, simulating alcohol.
They decrease seizures.
They decrease delirium.

Question 21

Acamprosate is administered to patients in alcohol withdrawal, what are its effects?

Answer 21

Antagonises NMDA (a stimulatory receptor)
Agonises GABA (similar to alcohol)

The aim is to simulate the effects of alcohol.

Question 22

“Wine (particularly red) affords more Cardiovascular Heart Disease protection than beer or sprits.”

What is the confounding factor in this claim?

Answer 22

People who don’t drink wine tend to smoke more and drink more. Those who enjoy wine also tend to have a healthier diet.

Question 23

What are the two reasons that women are more sensitive to alcohol?

Answer 23

1. Smaller Vd
2. Less activity (approximately 50% less than men) of gastric alcohol dehydrogenase.

These result in a higher plasma concentration of alcohol.

Question 24

Alcohol causes diuresis due to:

Answer 24

Decreased ADH release, decreasing water reabsorption.

Question 25

Some drugs that compete with alcohol’s enzymes (and competitively antagonise one another) are?

Answer 25

Warfarin
Barbituates
Steroids

Question 26

Alcohol has surprisingly has no effect on the GIT, true or false?

Answer 26

False.

15-20% chance of mucosal irritation.
Varicose veins can form in the oesophagus and duodenum
Also possible to have chronic: gastritis, pancreatitis and gallbladded inflammation.

Question 27

Ethanol and hypertension are:

(a) Positively correlated
(b) Negatively correlated
(c) Not at all correlated

Answer 27

(a) Positively correlated

Question 28

“Rum-Fits” in stage II of alcohol withdrawal usually occur how long after the last drink? What is the chance of having one seizure?

Answer 28

48-72hrs.

About a 50% chance of a pt having one seizure.

Question 29

Explain how GABA channels function.

Answer 29

They are ionotopic (ligand-gated) channels that cause an influx of Cl- ions.

This leads to hyperpolarisation of the cell, leading it be less likely to be excited. Hence, the inhibitory action of the GABA neurotransmitter.

Question 30

“Delirium Tremens” usually occurs in what stage of alcohol withdrawal? Is it common amongst all withdrawal patients?

Answer 30

Stage III.

No, it is only common in severe withdrawal patients.

Question 31

Alcohol dehydrogenase performs a ________ reaction on the substrate __________ to produce __________

Answer 31

Alcohol dehydrogenase performs a oxidation reaction on the substrate alcohol to produce acetylaldehyde

Question 32

Which is better at activating GABA receptors, benzodiazepines or alcohol?

Answer 32

Benzodiazepines.

Question 33

Name the four main effects of chronic alcohol consumption.

Answer 33

1. Peripheral neuropathy
2. Wernicke-Korsakoff Syndrome
3. Dementia
4. Cerebellar degeneration

Question 34

Antihistamines affect peak blood alcohol concentration how?

Answer 34

Inhibits gastric alcohol dehydrogenase, meaning lower gastric metabolism, causing a higher concentration in the plasma.

Question 35

Consuming food prior to drinking affects pharmacokinetics in what two ways?

Answer 35

Slows absorption and reduces peak plasma concentration of alcohol.

Question 36

Irreversible neurological abnormalities from chronic alcohol toxicity result from which two chemical byproducts?

Answer 36

Acetylaldehyde and Fatty-Acid Esters.

Question 37

“Alcohol is the cause of lower risk for Cardiovascular Heart Disease in moderate drinkers.”

What is the confounding factor of this claim?

Answer 37

People who moderately drink tend to also regularly exercise.