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alcohol_physiology.ppt
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What is this drug?

  • Alcohol is a psychoactive drug that is a CNS depressant.
  • Some claim that alcohol is the most widely consumed drug in the world and for some is as much a part of daily life as eating.

© AbleStock

Four types of alcohol

Methyl alcohol – poisonous

Isopropyl alcohol – poisonous

Ethylene glycol – poisonous

Ethanol – drinking alcohol

  • World’s most important psychoactive drug
  • Alcoholic beverages have been consumed for thousands of years, perhaps as far back as 8000 BC
  • A central nervous system depressant
  • Society’s love-hate relationship with alcohol

Social lubricant?

Adjunct to a fine meal?

“Demon rum”?

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Image sources: PhotoAlto/PunchStock (Image Ch09_33RedWineGrapes); Burke/Triolo Productions/Getty Images (Image Ch09_32ChiantiBottle)

  • Fermentation = the production of alcohol from sugars through the action of yeasts

Forms the basis of all alcoholic beverages

  • Fruits + yeast = fermentation will begin

Fruits naturally contain sugar

  • Cereal grains contain starch, which must be converted to sugar by malt before fermentation can begin
  • Yeast has a limited tolerance for alcohol

When alcohol concentration reaches 15 percent, the yeast dies and fermentation ceases

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  • Distillation = evaporation and condensing of alcohol vapors to produce beverages with alcohol content higher than 15 percent

First used in Arabia around AD 800

Introduced into Europe in about the 10th century

In U.S., began on a large scale at the end of the 18th century

  • Proof = alcohol content of a distilled beverage; twice the percentage of alcohol by weight

90-proof whiskey is 45 percent alcohol

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  • Standard drink has about 0.5 ounce of pure alcohol

12-ounce beer

4 ounces of wine

1 ounce of 100-proof spirits

© 2008 McGraw-Hill Higher Education. All rights reserved.

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Image source: The McGraw-Hill Companies, Inc./Jill Braaten, photographer (Image Ch09_01AlcoholicEquivalentsProof)

Per capita ethanol consumption by beverage type

Source: NIAAA Surveillance Report No. 73

© 2008 McGraw-Hill Higher Education. All rights reserved.

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Figure 9.1 from text

Total estimated U.S. per capita ethanol consumption in gallons per year by state

Source: Data from NIAAA

© 2008 McGraw-Hill Higher Education. All rights reserved.

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Figure 9.2 from text

  • Gender differences: Males more likely to drink than females, and more likely to drink more
  • Drinking among college students

College students drink more than their nonstudent peers

Many campuses have banned sale and advertising of alcohol, and many fraternities have banned keg parties

Alcohol use and drinking behavior hasn’t changed significantly in response

Today’s college students are less likely to drink and drive compared to students in the early 1980s

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Fig

3.1

Age in Years

12-13

14-15

16-17

18-20

21-25

26-29

30-34

35-39

40-44

45-49

50-54

55-59

60-64

65+

Percent Using in Past Month

4.5

17.0

31.8

51.5

67.8

61.7

59.2

59.5

58.6

57.7

54.0

52.9

46.2

34.4

Current Use

Heavy Alcohol Use

Binge Use

  • Absorption

Some absorbed in the stomach, most in the small intestine

Absorption is slower if there is food or water in the stomach

Absorption is faster in the presence of carbonated beverages

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  • Distribution

Blood alcohol concentration (BAC) is a measure of the concentration of alcohol in blood, expressed as a percentage in terms of grams per 100 ml

Alcohol is distributed throughout body fluids

Alcohol is less distributed in fatty tissues, so a lean person will have a lower BAC than a fatter person

  • Metabolism: Liver metabolizes about 0.25 ounce of alcohol per hour

If rate of intake = rate of metabolism, BAC is stable

If rate of intake exceeds rate of metabolism, BAC climbs

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The relationship between blood alcohol concentration and alcohol intake

© 2008 McGraw-Hill Higher Education. All rights reserved.

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Figure 9.3 from text

  • Women tend to be more susceptible than men to the effects of alcohol after consuming the same amount

Stomach enzyme that metabolizes a small amount of alcohol is more active in men

Women absorb a greater proportion of the alcohol they drink

Women tend to weigh less and have a higher proportion of body fat

“Tank” into which alcohol is added is smaller

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Image source: Steve Mason/Getty Images (Image Ch09_19GenderDifferences)

Tolerance, food in stomach, carbonation,

Other medications,

  • BAC produced depends on

Presence of food in the stomach

Rate of alcohol consumption

Concentration of alcohol

Drinker’s body composition

  • Alcoholic beverages have no vitamins, minerals, protein, or fat—just a large amount of carbohydrates and associated calories.
BAC (%) Behavioral Effects
0.05 Lowered alertness, release of inhibitions, impaired judgment
0.10 Slower reaction times, impaired motor function, less caution
0.15 Large, consistent increases in reaction time
0.20 Marked depression in sensory and motor capability, intoxication
0.25 Severe motor disturbance, staggering, great impairment
0.30 Stuporous but conscious—no comprehension of what’s going on
0.35 Surgical anesthesia; about LD1, minimal level causing death
0.40 About LD50

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  • Almost 95% of consumed alcohol is inactivated by liver metabolism.
  • The liver metabolizes alcohol at a slow and constant rate and is unaffected by the amount ingested.
  • Thus, if one can of beer is consumed each hour, the BAC will remain constant.
  • Central nervous system depressant
  • Used as anesthetic until the late 19th century
  • Alcohol has many effects on the brain and the mechanisms are difficult to pin down

Similar to barbiturates and benzodiazepines, it enhances the inhibitory effect of GABA at the GABA-A receptor

At high doses, it blocks the effects of the excitatory transmitter glutamate

It affects dopamine, serotonin, and acetylcholine neurons

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  • Peripheral circulation: Dilation of peripheral blood vessels means that drinkers lose body heat but feel warm
  • Fluid balance: Alcohol has a diuretic effect that can lower blood pressure in some people
  • Hormonal effects: Chronic abusers of alcohol can develop a variety of hormone-related disorders

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  • Low to moderate doses

Disinhibition

Social setting and mental state may determine individual response

Euphoric, friendly, and talkative

Aggressive and hostile

Interfere with motor activity, reflexes, and coordination

  • Moderate quantities

Slightly increases heart rate

Slightly dilates blood vessels in arms, legs, and skin

Moderately lowers blood pressure

Stimulates appetite

Increases production of gastric secretions

Increases urine output

  • At higher doses

Social setting has little influence on effects

Difficulty in walking, talking, and thinking

Induces drowsiness and causes sleep

Induces a hangover when drinking stops

  • Large amounts consumed rapidly

Severe depression of the brain system and motor control area of the brain

Lack of coordination, confusion, and disorientation

Stupor, anesthesia, coma, or death

  • Lethal level of alcohol between 0.4 and 0.6 by volume in the blood
  • Drinking black coffee, taking a cold shower, or breathing pure oxygen will hasten the sobering up process.
  • The type of alcohol beverage you drink can influence the hangover that results.
  • Taking an aspirin-caffeine combination after drinking helps the sobering up process and the chances of having a hangover.
  • About 2% of alcohol is excreted unchanged
  • About 90% is metabolized in the liver

Alcohol

Acetaldehyde

Acetic acid

Alcohol dehydrogenase

Aldehyde dehydrogenase

© 2008 McGraw-Hill Higher Education. All rights reserved.

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  • Exercise, coffee, and other strategies do not speed up the rate of metabolism
  • Liver responds to chronic intake of alcohol by increasing enzyme activity

Contributes to tolerance among heavy users

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  • Symptoms: upset stomach, fatigue, headache, thirst, depression, anxiety, and general malaise
  • Possible causes: alcohol withdrawal, exposure to congeners, cellular dehydration, gastric irritation, reduced blood sugar, and/or the accumulation of acetaldehyde
  • Moderate drinking is the only way to avoid a hangover

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Image source: Royalty-Free/Corbis (Image Ch09_26Hangover)

  • Abstinence syndrome is medically more severe and more deadly than opioid withdrawal
  • Abstinence syndrome occurs in stages

Stage 1: tremors, rapid heartbeat, hypertension, heavy sweating, loss of appetite, insomnia

Stage 2: hallucinations (auditory, visual, and/or tactile)

Stage 3: delusions, disorientation, delirium

Stage 4: seizures

  • Initial detoxification should be carried out in an inpatient medical setting
  • Sedatives given in stage 1 or 2 prevents stages 3 and 4
  • Some symptoms can last for up to several weeks

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  • Alcohol can cause severe physical and psychological dependence.

Cross-tolerance

Behavioral tolerance: Compensation of motor impairments through behavioral pattern modification by chronic alcohol users

  • The common practice of taking alcohol concurrently with other drugs.

© AbleStock

  • Reasons why individuals may combine alcohol with other drugs:

Alcohol enhances properties of other CNS depressants.

Decreases the amount of an expensive and difficult-to-get drug required to achieve the desired effect.

Helps diminishes side effects of other drugs.

There is a common predisposition to use alcohol and other drugs.

  • Alcohol overdose (poisoning) is common and dangerous
  • If someone drinks enough to pass out

Place her or him on side and monitor breathing OR take to ER

Do not leave the person alone

  • If someone drinks enough to vomit

He or she should stop drinking

Vomiting reflex indicates a rapidly rising BAC but is suppressed at BACs above 0.20 percent

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Image source: Ryan McVay/Getty Images (Image Ch09_25AlcoholToxicity)

  • Brain tissue loss and intellectual impairment
  • Liver disease: hepatitis, fatty liver, cirrhosis (see right)
  • Heart disease: cardiomyopathy, heart attack, hypertension, stroke
  • Alcohol’s effects on HDL may reduce heart attack risk among moderate drinkers
  • Cancer
  • Impaired immunity

© 2008 McGraw-Hill Higher Education. All rights reserved.

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Image source: Centers for Disease Control and Prevention/ Dr. Edwin P. Ewing, Jr. (Image Ch09_27Cirrhosis)

  • FAS = a collection of physical and behavioral abnormalities caused by the presence of alcohol during fetal development
  • Diagnostic criteria

Growth retardation before and/or after birth

  • Pattern of abnormal features of the face and head
  • Evidence of central nervous system abnormality

© 2008 McGraw-Hill Higher Education. All rights reserved.

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Image source: National Institute on Alcohol Abuse and Alcoholism (http://www.niaaa.nih.gov/Resources/GraphicsGallery/FetalAlcoholSyndrome/FetalAlcohol.htm)

(Image Ch09_28FASChild)

  • Fetal alcohol syndrome

Related to peak BAC and to duration of alcohol exposure

Prevalence: 0.2 to 1.5 per 1000 births

  • Fetal alcohol effects

All alcohol-related developmental abnormalities associated with prenatal alcohol exposure

Prevalence: 80 to 200 per 1000 births

  • Drinking during pregnancy increases risk of spontaneous abortion
  • Data do not prove that low levels of alcohol use during pregnancy are safe or that they are unsafe

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Dependence

  • 12.5 million alcoholics in United States
  • Approximately 50% high school seniors get drunk annually
  • Recovered alcoholics are more likely to relapse when under stress
  • Recovery from alcoholism is a long-term process

  • APA defines substance abuse and dependence and includes alcohol as a psychoactive substances

Alcohol abuse is a maladaptive pattern indicated by continued use despite knowledge of having persistent problems caused by alcohol

Alcohol dependence involves more serious psychosocial characteristics and includes the physiological factors of tolerance and withdrawal among the possible symptoms

  • Cognitive and genetic factors are potential underlying causes of dependence

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  • Alcoholics Anonymous view—alcohol dependence as a disease—became popular beginning in the 1940s and 1950s

A progressive disease characterized by loss of control over drinking

Only treatment is abstinence from alcohol

Disease model: alcohol dependence is the primary disease and not the result of another underlying cause

  • Criticisms of disease model

What is the cause of the disease?

Why don’t all dependent drinkers exhibit the same symptoms?

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  • There is no agreement regarding at what specific point someone is an alcoholic.
  • Alcoholism is a state of physical and psychological addiction to a psychoactive substance known as ethanol.
  • Most definitions include chronic behavioral disorders, repeated drinking to the point of loss of control, health disorders, and difficulty functioning socially and economically.

World Health Organization (WHO) definition:

  • “Alcohol dependence syndrome
    is characterized by a state, psychic
    and usually also physical, resulting
    from drinking alcohol. This state is
    characterized by behavioral and
    other responses that include a compulsion to take alcohol on a continuous or periodic basis to experience its psychic effects and sometimes to avoid the discomfort of its absence; tolerance may or may not be present” (NIAAA, 1980).

© Corbis

  • “Alcoholism is a chronic behavioral disorder manifested by repeated drinking of alcoholic beverages in excess of the dietary and social uses of the community, and to an extent that interferes with the drinker’s health or his social or economic functioning” (Keller, 1958).

  • “Alcoholism is a chronic, primary,
    hereditary disease that progresses
    from an early, physiological
    susceptibility into an addiction
    characterized by tolerance changes,
    physiological dependence, and loss
    of control over drinking.
    Psychological symptoms are
    secondary to the physiological
    disease and not relevant to its onset’’
    (Gold, 1991).


© Pixtal/age fotostock

Major Known Components of Alcoholism

  • Craving: A compulsion to drink alcohol even during inappropriate times (e.g., while driving, working, at a formal event)
  • Very impaired or loss of control: Inability to limit drinking once begun
  • Physical dependence: Withdrawal symptoms when attempting to abstain (e.g., nausea, sweating, anxiety)
  • Tolerance: Need to increase usage to achieve the effect, the “buzz” from alcohol

  • Alpha alcoholics: Mostly a psychological dependence
  • Beta alcoholics: Mostly socially dependent on alcohol
  • Gamma alcoholics: Most severe; suffers from emotional and psychological impairment
  • Delta alcoholics: Constantly losing control over the amount of alcohol consumed
  • Epsilon alcoholics: Constantly binge drinking and at times days at a time
  • Zeta alcoholics: Moderate drinker who becomes abusive and violent

  • Young Adult (31.5% of U.S. alcoholics): Young adult drinkers without major problems regarding their drinking
  • Young Antisocial (21% of U.S. alcoholics): Mid-20s, had earlier onset of regular drinking and alcohol problems, and come from heavy alcohol use families
  • Functional (19.5% of U.S. alcoholics): Middle-aged, well-educated, with stable jobs and families
  • Intermediate Familial (19% of U.S. alcoholics): Middle-aged, with 50% from families with multigenerational alcoholism
  • Chronic Severe (9% of U.S. alcoholics): Mostly middle-aged, high rates of antisocial personality disorder and criminality

  • Drinking and driving: On most
    weekend nights throughout the
    United States, 70% of all fatal
    single-vehicle crashes involve a
    driver who is legally intoxicated.
  • Income/wealth: Less affluent
    people drink less than more affluent individuals.
  • The average “alcoholic”: The largest percentage of alcoholics are secret or disguised drinkers who look very much like common working people.
  • On average: Most people who consume alcohol do not become problem drinkers.

© Marcin Balcerzak/ShutterStock, Inc.

  • Co-dependency (or co-alcoholism): A relationship pattern in which addicted or nonaddicted family members identify with the alcohol addict and deny the existence of alcohol consumption as a problem.
  • Enabling: Denial or making
    up of excuses for the excessive

drinking of an alcohol addict to

whom someone is close.

© Jones and Bartlett Publishers/Photographed by Kimberly Potvin and Christine McKeen

  • Children of alcoholics (COAs) 2–4 times more likely to become alcoholics themselves.
  • Adult children of alcoholics (ACOAs) 2–4 times more likely to develop alcoholism.
  • Approximately, 9.7 million children age 17 or younger are living in households with one or more adults classified as having an alcohol abuse or dependence problem.

Seventy percent of these children were biological, foster, adopted, or stepchildren.

As a result, 6.8 million children, or about 15% of children aged 17 or younger, meet the formal definition of children of alcoholics.

  • COAs and ACOAs are more likely to marry into families where alcoholism is prevalent.
  • Twenty-five percent of American children are exposed to an alcoholic before the age of 18.

  • Psychodrama: A family therapy in which significant inter- and intra-personal issues are enacted in a focused setting using dramatic techniques.
  • Genogram: A family therapy technique that records information about behavior and relationships on a type of family tree to elucidate persistent patterns of dysfunctional behavior.
  • Role-playing: A therapeutic technique in which group members play assigned parts to elicit emotional actors.

  • Post-traumatic stress disorder: A psychiatric syndrome in which an individual who has been exposed to a traumatic event or situation experiences psychological stress that may manifest itself in a wide range of symptoms, including re-experiencing the trauma, numbing of general responsiveness, and hyper-arousal.

  • Treatment of alcoholism

Denial as a psychological defense

Easy to relapse without radical shift in lifestyle

Alcohol rehabilitation and medical ramifications

More emotionally fragile than other addicts

Relapsing syndrome

  • Relapsing syndrome: Returning to the use of alcohol after quitting.
  • Acute alcohol withdrawal syndrome: Symptoms that occur when an alcohol addicted individual does not maintain his/her usual blood alcohol level.
  • Delirium tremens: The most severe, even life-threatening, form of alcohol withdrawal, involving hallucinations, deliriums, and fever.

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