Chapter 1 - Alcohol

Alcohol Absorption

• 20% absorbed through stomach• 80% absorbed through small intestine• Equilibration: alcohol is absorbed and

distributed evenly throughout the body• Before equilibration: higher concentration in

brain than in blood• Food in stomach: main influence on

absorption. No food:1 hr. Food:2 hrs.

• Type of drink: beer – more slowly absorbed• Body weight

Alcohol Elimination

• 95% metabolized before excretion• 5% eliminated unchanged-urine and lungs• Most – metabolized by liver• Alcohol dehydrogenase (ADH) breaks down

alcohol into acetaldehyde• Acetaldehyde is broken down by acetaldehyde

dehydrogenase into acetate-then excreted

• Accumulation of acetaldehyde-nausea (Antabuse)

• approx. 1 drink per hour• Drink more that 1 per hour: liver metabolizes

other drugs faster (Plavix, Tylenol)• Cross tolerance: barbiturates

Acute Exposure

• Different effects-different people• 1-4 drinks-judgment, reaction time, motor

coordination• 4-12 drinks-motor coordination, reflexes• 12-16 drinks-voluntary responses to stimuli• 16-24 drinks- sensations, movement

• 24-30 drinks -breathing;heart• Move from happy-death

Effects on Brain Cells

• Lesioning in animals• CNS depressant• Biphasic action-low doses-activates some

cells-feel stimulated• GABA – inhibitory• Glutamate – excitatory• NMBA – subtype of glutamate receptor-

essential for new memories

• Dopamine-increases release in reward centers• Only when blood alcohol levels are rising• When levels go down, drink more

• Memory: blackouts; not only in heavy drinkers; college students-40%-sex, fights, driving

• Hangover: headache-bloodvessels and fluid balances in body

• Take pain reliever before bed• Nausea-harder to treat• Coffee-may upset stomach; dehydration

Violence and Aggression

• 50-60% murders; 40% male sexual aggression; 60-70% male instigated domestic violence

Chronic Effects

• Brain shrinkage? Yes-long-term heavy use• Stop drinking-volume can return• Frontal Lobe-executive functions; especially

vulnerable• Mammillary bodies-base of brain-memory• hippocampus-new memories• New studies-moderate drinking can kill cells• Binging-brain damage

Effects on Mental Function

• Memory formation-new memories• Abstract thinking• Problem solving-lack mental flexibility• Attention and concentration• Perception of emotions• Will problems go away?

Other Brain Problems

• Wernicke’s disease-confusion, abnormal eye movements, lack of coordination

• Deficiency of thiamine• About 15% respond well to vitamin therapy and

abstinance• Korsakoff’s psychosis-can’t form new

memories; old memories are patchy; about 20% completely recover;60% partially; 20% institutionalization

Liver Disease

• Fatty liver-reversible• Alcoholic hepatitis-reversible• Cirrhosis-later stages-not reversible• Social drinkers-pattern of drinking is

important; the more alcohol each session, the higher the chance of problems

• 3 drinks per day-substantial risk of developing permanent cognitive impairments

Tolerance and Dependence

• Alcohol dependence (alcoholism)-abnormal seeking, lack of control, withdrawal

• Alcohol abuse-health problems, social problems, or both

Fetal Effects

• FAS-Fetal Alcohol Syndrome: slower growth0prenatal and postnatal; facial abnormalities; CNS abnormalities (mental retardation.

• FAE-Fetal Alcohol Effects: more moderate drinking; behaviors similar to ADD

• FASD-Fetal Alcohol Spectrum Disorders: includes all neurological, cognitive, behavioral,and learning problems

Why Addiction?

• Genetic Factors: family studies, twins, adoption

• Concordance rate-identical twins-58%• No study has conclusively demonstrated a

genetic basis for alcoholism• Men-sons of alcoholic fathers-seem more

affected by pleasurable effects-likely to continue drinking

Type I• After 25 • Infrequent ability to abstain• Infrequent fights and arrests• Infrequent dependence (loss of

control)• Frequent fear and guilt about

alcoholism• Male and female• Extent of genetic influences-moderate• Extent of environmental influences-

high• Serotonin abnormalities in the brain-

absent

Type II• Before 25• Frequent• Frequent

• Frequent

• Infrequent

• Male only• Extent of genetic influences-high• Extent of environmental influences-low • Serotonin abnormalities in the brain-

present

Special Considerations-Women

• Usually smaller; larger % of body fat=higher concentrations in blood

• Less alcohol dehydrogenase• May have blood alcohol levels 25-30% higher than

men after drinking same amount• Birth control pills-slow down elimination• Greater risk-liver damage, even drinking less• Greater risk-pancreatic damage;damaged

pancreas;enzymes leak out; start to digest pancreas

• More likely-high blood pressure; 2-3 drinks per day-40% greater risk

• Breast cancer-2-4 drinks per day-41% increased risk

• More sensitive to brain effects• Divorce rate-higher for alcoholic women• At greater risk for domestic violence and

sexual assault

Children and Adolescents

• “Binge drinking”: Men-5+ drinks; Women-4+• Brain-not fully developed-mid twenties

(especially frontal lobe)• More susceptible to effects on learning and

memory; smaller hippocampus; cells don’t develop as quickly

• Earlier start-more problems later

Interactions With Other Drugs

• Addition: two drugs in combination produce a greater effect than either drug separately

• Synergism: greater than an additive effect• Potentiation: a synergistic interaction; one drug

combined with another produces enhanced effect when one of the drugs alone would have no effect

• Antagonism: effect of a drug is diminished when used with another

• Drug A = 0• Drug B = 20• Drug C = 35• Drug A combined with Drug B = 30• Drug B combined with Drug C = 55• Drug A combined with Drug C = 15• Drug B combined with Drug C = 85

• Synergistic effects: Alcohol with barbiturates, heart meds, insulin, anti-inflammatory drugs, painkillers, tranquilizers, some antibiotics, Tagamet (heartburn)

• Antagonistic effects: Morphine with naloxone or naltrexone; some antidepressants with bran, oatmeal, high fiber foods

Health Benefits?• Relax; reduce stress• Light drinkers-reduced risk for coronary artery disease; 1-1 ½

drinks/day• Harvard Medical School Study-22,000 men;ages 40-84; 10 years;

those who drank 2-4 drinks per week: less likely to die with heart problems than men who drank <1

• Also fewer cancers• Death rate: 2+ a day-51% higher• Conclusion: 2 drinks/week, good; 2 drinks/day, bad• Large studies-Asia & Europe-light/moderate drinking may diminish

risk of death-middle aged men• Interpret results with caution