Alcohol 1 Flashcards
Current Drinker
Have had one drink in the past 30 days
Binge Use
Have had 5 or more drinks in the past 30 days
Heavy Use
Have had 5 or more drinks on 5 or more occasions in the past 30 days
Drinks with the same alcoholic content
All at .6 oz of alcohol Beer- 12 oz Malt Beer- 8 oz Table Wine- 5 oz Fortified Wine- 3.5 oz Cordial Liquer- 2.5 oz Brandy- 1.5 oz 80 Proof Shot- 1.5 oz
Absorption
Rapidly absorbed via the GI tract
Subjected effects detected quickly- some may be due to expectancy
Plasma ethanol levels of 20 mg/dl can be detected
Placebo use due to olfactory and taste factors
Excretion/Absorption
Stomach serves as holding area- contains 20% of ethanol
92-94 % of ethanol absorbed metabolized and excreted
Remaining is directly excreted through sweat, tears, and breath
Racial Differences
Asian populations have low levels of alcohol dehydrogenase - increased flushing and greater levels of intoxication
Due to genetic variation between ethnicities
Enzyme Location
80-90% of alcohol dehydrogenase in the liver
Both enzymes are polypeptides, and are genetically controlled
Breathalyzer
Direct excretion through the breath is basis of breathalyzer
Ethanol concentration is in equilibrium between blood and tissues
Alveolar sacs are right next to capillaries
Values parallel the blood, except are artificially higher directly after drinking
Factors that speed absorption
- Carbonation- Speeds gastric emptying rate
- Aspirin- irritates gastric walls and causes faster gastric emptying rate
- Empty stomach- causes alcohol to go straight to small intestine
Factors that slow absorption
Food- slows gastric emptying rate
Water- Dilutes concentration
Marihuana- slows GI motility
Male/ Female Differences
Females have higher BAL with same amount of alcohol
Males typically have a higher muscle to fat ratio- alcohol is more diluted
Females with a higher fat ratio than males- alcohol not fat soluble, so it is concentrated in plasma
Females have 50% less gastric alcohol dehydrogenase than males
Theories on Mechanism of Action
Lipid Theory- Alcohol perturbates cellular membranes at the CNS
Protein Theory- Alcohol interacts with a neuronal protein site, neurotransmitter ion gates
Alcohol has some effect on protein function
Alcohol Sensitive Neurotransmitters
GABA Glutamate Dopamine Serotonin Nicotinic Acetylcholinergic
GABA
Major inhibitory neurotransmitter
Stimulation results in dampening of the signal
Receptor of several complex proteins
Activity of protein kinase C controls GABAa sensitivity to alcohol
Binding to GABA causes Cl ions to flow into the cell- ethanol enhances this
As a result, reduced anxiety and reduced motor coordination
Another binding site of these receptors for benzodiazepines
Glutamate
Major excitatory transmitter
Accounts for 40% of transmitters
NMDA subtype
Involved with learning and memory
May be involved in physical dependence
Normally allows Ca2+ to flow into the cell
Ethanol dampens Ca2+ flow into the cell by inhibiting NMDA like glutamate receptors
CNS and Physiological Effects
Euphoria- sense of well being, greater self esteem, feelings of confidence, increased talking and social ability
Varied effects on heart rate and blood pressure
Increased skin temperature due to vasodilation
Rate of Consumption vs BAC
Higher BAC with increased rates of consumption
Metabolism
Alcohol Dehydrogenase in liver- first line in breaking alcohol down- rate limiting step
Individual variations in rate, but falls within a predictable range of between 12-20 mg/dL/hr
Remains constant within an individual
Alcohol –> Acetaldehyde –> Acetate
Acetaldehyde
Generally toxic to tissues in the body- irritant to skin and carcinogen
Causes a number of negative signs and symptoms- nausea, vomiting, facial flushing, headache, heart palpitations
Major contributor to hangovers
Buildup causes Alcohol Flush Reactions
Aldehyde Dehydrogenase
- Acetic acid is less toxic to the body
- Polymorphic variants on the genes that encode ALDH that alter the kinetic profile
- Mutant form of ALDH genes causes low levels of enzyme that results in high amounts of flushing and intoxication
Social
Small amount on occasional basis
Spree
Binge drink occasionally, but stay sober for the most part
France drinkers
Consume large amounts of alcohol over a long time period
Chronic Alcoholic drinking pattern
Drink heavily for a few days, and then go on a self imposed sober period for 2-3 days. Then repeat this cycle
Functional Tolerance
NMDA receptors allow for Ca2+ to flow into the cell
Ethanol dampens NMDA stimulated Ca2+ flow
Tolerance develops at different rates to different effects- more quickly to mental functions, less quickly to motor control
Brain compensates by up-regulating and decreasing sensitivity at these receptors
Rapid tolerance to unpleasant effects of alcohol increase alcohol consumption
Reverse Tolerance
Increased sensitivity to alcohol after major liver damage
Metabolic Tolerance
Resistance to alcohols effects by increasing the enzymes that break alcohol down
Increased rate in breaking alcohol down
Behavioral Tolerance
Resistance to alcohol’s effects that develops with repeated experiences of intoxication
Learned associations
Behaviors learned when intoxicated are better performed later when equally intoxicated
Physical Dependence
Results in hyper excitability during withdrawal period
8-12 hours after last drink
Begin: Mild agitation, nausea, vomiting, sweating, tremors, irregular heart rate
Hallucinations, clouded senses, seizures and delirium follow
Acute phase can last 7-10 days
Delirium tremens characterized with profound disorientation, perception disorders, severe tremors, restlessness and hallucination
Rare now with improved treatment of benzodiazepines, but death is possible
Alcohol Blackouts are not
- Act of passing out
- Only happen to chronic alcoholics
- Only happen at excessively high BAC
- Can only happen when doing shots
- Early signs of dementia
Alcohol blackouts
Loss of memory during certain time points of alcohol consumption
Interfere with processing that allows short term memory to be converted into long term meory
Can carry conversations, drive, but cannot remember what was done minutes before
Long term memory remains intact
Both in social and heavy drinkers
Complete (en bloc, or fragmentary)
Complete- full loss of any memories for the time period when drinking
Alcohol Blackout Risk Factors
Women at higher risk
When taken with other amnesia causing drugs
High BAC
Combining with other psychoactive drugs like marihuana
Personal Breathalyzers
Handheld devices
Advertised to avoid getting a ticket, or to know BAC levels
On Roads
Sobriety Checkpoints- Locations where law enforcement officers assess drivers BAC
Ignition Interlocks- Car will not start without a low BAC
Public Health Issue
- Alcohol related incidences are 1/3 of all traffic related deaths
- Fatal crashes include younger populations
