Alcohol Flashcards
Disulfram or ANTABUSE is administed to alcoholics when? What are its intended effects?
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.
Are chronic alcoholics more or less sensitive to barbituates? Why?
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.
What is the characteristic response to alcohol?
Euphoria, impaired thought process and decreased motor control.
Alcohol is:
- An agonist of the ______ receptor
- An antagonist of the ______ receptor
- Activates the release of _______ and ________
- An agonist of the GABA receptor
- An antagonist of the NMDA receptor
- Activates the release of serotonin and dopamine
Why does alcohol cause vasodilation?
Due to central vasomotor depression. This leads to decreased innervation of smooth muscle, leading to vasodilation.
Peak levels of plasma alcohol concentration occurs how long after consumption?
30 to 90 minutes.
What other drugs also have the same effect as Disulfram?
Cephalosporins and sulphonylurea.
Sulphonylurea are a group of anti-diabetic drugs have the same effect.
The accumulation of acetylaldehyde in the body leads to whcih four symptoms?
- Headache
- Nausea
- Gastritis
- Dizziness
Early on, alcohol impairs thought and motor processes dependent on:
Judgement, training and previous experience.
True or false, acetylaldehyde is the final metabolic product of alcohol.
False. The final metabolic byproduct of alcohol is acetic acid.
Alcoholics gaining the majority of their calories from alcohol results in a deficiency in _______?
Thiamine.
Why does alcohol abuse cause hepatitis?
- Increased fat accumulation in the liver.
- Increased fatty acid release from fat cells.
- Decreased fatty acid oxidation.
Which stage of alcohol withdrawal has a high rate of mortality? How long is this after the last drink?
Stage III, “Delirium Tremens”.
It occurs 72-96hrs after the last drink.
How significant is the rate of excretion of alcohol to plasma concentration changes?
Not very significant. Most alcohol is metabolised.
What anti-psychotics are commonly used in the treatment of alcohol withdrawal?
Haloperidol.
Droperidol.
Will the use of diuretics assist in lowering BAC? Why or why not?
No.
Alcohol is mostly metabolised, not excreted. So increasing the rate of excretion will not lead to a lower plasma concentration.
Thiamine is also known as? It is commonly deficient in which syndrome?
Thiamine is also known as Vitamin B1. It is commonly deficient in Wernicke-Korsakoff syndrome.
Explain the cellular mechanisms of tolerance to alcohol.
- More Ca2+ channels - leading to more vesicle release, less depressant effect in the brain.
- Increased NMDA receptors - more likely to have stimulation, meaning depressants have less signal.
- Decreased GABA receptors - less chance of binding to GABA and causing depressant effects.
Explain how the concentration of alcohol consumed affects pharmacokinetics.
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.
Why are benzodiazepines used in the Rx of alcohol withdrawal?
The increase the effect of GABA receptors, simulating alcohol.
They decrease seizures.
They decrease delirium.
Acamprosate is administered to patients in alcohol withdrawal, what are its effects?
Antagonises NMDA (a stimulatory receptor) Agonises GABA (similar to alcohol)
The aim is to simulate the effects of alcohol.
“Wine (particularly red) affords more Cardiovascular Heart Disease protection than beer or sprits.”
What is the confounding factor in this claim?
People who don’t drink wine tend to smoke more and drink more. Those who enjoy wine also tend to have a healthier diet.
What are the two reasons that women are more sensitive to alcohol?
- Smaller Vd
- Less activity (approximately 50% less than men) of gastric alcohol dehydrogenase.
These result in a higher plasma concentration of alcohol.
Alcohol causes diuresis due to:
Decreased ADH release, decreasing water reabsorption.
Some drugs that compete with alcohol’s enzymes (and competitively antagonise one another) are?
Warfarin
Barbituates
Steroids
Alcohol has surprisingly has no effect on the GIT, true or false?
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.
Ethanol and hypertension are:
(a) Positively correlated
(b) Negatively correlated
(c) Not at all correlated
(a) Positively correlated
“Rum-Fits” in stage II of alcohol withdrawal usually occur how long after the last drink? What is the chance of having one seizure?
48-72hrs.
About a 50% chance of a pt having one seizure.
Explain how GABA channels function.
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.
“Delirium Tremens” usually occurs in what stage of alcohol withdrawal? Is it common amongst all withdrawal patients?
Stage III.
No, it is only common in severe withdrawal patients.
Alcohol dehydrogenase performs a ________ reaction on the substrate __________ to produce __________
Alcohol dehydrogenase performs a oxidation reaction on the substrate alcohol to produce acetylaldehyde
Which is better at activating GABA receptors, benzodiazepines or alcohol?
Benzodiazepines.
Name the four main effects of chronic alcohol consumption.
- Peripheral neuropathy
- Wernicke-Korsakoff Syndrome
- Dementia
- Cerebellar degeneration
Antihistamines affect peak blood alcohol concentration how?
Inhibits gastric alcohol dehydrogenase, meaning lower gastric metabolism, causing a higher concentration in the plasma.
Consuming food prior to drinking affects pharmacokinetics in what two ways?
Slows absorption and reduces peak plasma concentration of alcohol.
Irreversible neurological abnormalities from chronic alcohol toxicity result from which two chemical byproducts?
Acetylaldehyde and Fatty-Acid Esters.
“Alcohol is the cause of lower risk for Cardiovascular Heart Disease in moderate drinkers.”
What is the confounding factor of this claim?
People who moderately drink tend to also regularly exercise.
