2. Loarning outcome
• Upon successful completion of this topic, students
should be able to
– Describe the varying blood alcohol concentration
(BAC) with its implication.
– Pharmacological actions of alcohol on various
physiological systems.
3. Alcohol
• Alcohols are hydroxy derivatives of aliphatic
hydrocarbons. When unqualified, ‘alcohol’ refers to
ethyl alcohol or ethanol.
• Other forms of alcohol
– Absolute alcohol: 99% w/w ethanol (dehydrated
alcohol).
– Rectified spirit: 90% w/w ethyl alcohol produced from
fermented mollases, by distillation.
– Methylated spirit: Also called ‘denatured spirit’ is
produced by adding 5 parts of wood naphtha (methyl
alcohol) to 95 parts of rectified spirit
4. Pharmacology of alcohol
• Ethanol is highly lipid soluble and is absorbed rapidly
from the stomach and duodenum, and food
(especially milk, fat, and carbohydrates) slows and
decreases absorption. Peak ethanol levels are
generally achieved in 20 minutes to 1 hour of
ingestion.
• About 95% of ethanol is metabolized by alcohol
dehydrogenase to acetaldehyde and then by
aldehyde dehydrogenase to acetate in the liver and
the remainder is excreted in the breath, sweat, and
urine.
5. Pharmacology of alcohol
• Ethanol metabolism by alcohol dehydrogenase
follows first-order kinetics at low doses. However,
once the blood concentration exceeds 15 to 40
mg/dL/hr, it follows dose-dependent (zero-order)
kinetics.
• Tolerance and toxicity develop in habitual users due
to induction of the alcohol hepatic drug metabolizing
enzyme. Increased formation of metabolites
(acetaldehyde in the liver) results in toxicity leading
to organ damage.
6. Pharmacological actions
System Effect
CNS Alcohol is a neuronal depressant
CVS • Small doses: BP is not affected
• Moderate doses: cause tachycardia and a mild rise
in BP due to increased muscular activity and
sympathetic stimulation
• Large doses: cause direct myocardial as well as
vasomotor centre depression and there is fall in
BP.
Blood Regular intake of small to moderate amounts of
alcohol (1–2 drinks) has been found to raise HDL-
cholesterol levels and decrease LDL oxidation.
7. Pharmacological actions
System Effect
Body
temperature
Alcohol is reputed to combat cold. High doses
depress temperature regulating centre.
Respiration Direct action of alcohol on respiratory centre is a
depressant.
GIT Alcoholic beverages have variable effect on gastric
secretion depending on the beverage itself and
whether the individual likes it.
Liver Fatty liver. This is reversible but may progress to
cirrhosis if prolonged or excessive.
Skeletal
muscle
• Fatigue is allayed by small doses
• Weakness and myopathy occurs in chronic
alcoholism
8. Pharmacological actions
System Effect
Kidney Diuresis. Inhibits ADH secretion. Alcohol does not
impair renal function.
Endocrine
effects
Moderate amounts of alcohol increase Adr release
which can cause hyperglycaemia and other
sympathetic effects.
Sex Alcohol is reputed as an aphrodisiac. Chronic
alcoholism can produce impotence, testicular
atrophy, gynaecomastia and infertility in both men
and women.
9. Clinical uses
• As antiseptic
• Alcoholic sponges have been used to reduce body
temperature in fever.
• Rubefacient and counterirritant for sprains and joint
pains.
• Intractable neuralgias (trigeminal and others), severe
cancer pain: Injection of alcohol round the nerve
causes permanent loss of transmission.
• As appetite stimulant and carminative
• To treat methanol poisoning
10. Toxicity
• A. Side effects of moderate drinking Nausea, vomiting,
flushing, hangover, traffic accidents.
• B. Acute alcoholic intoxication Unawareness,
unresponsiveness, stupor, hypotension, gastritis,
hypoglycaemia, respiratory depression, collapse, coma and
death (Treatment: Gastric lavage).
• C. Chronic alcoholism: Heavy drinking is often associated with
nutritional deficiencies. In addition to impaired mental and
physical performance, neurological afflictions are common -
polyneuritis, pellagra, tremors, seizures, loss of brain mass,
Wernicke’s encephalopathy, Korsakoff’s psychosis and
megaloblastic anaemia. Thiamine deficiency is very common
in chronic alcoholism.
11. Medicolegal importance of alcohol
• Blood concentration of alcohol has medicolegal
importance. Because there is a constant blood-to-
breath ratio of 2100:1, a breath sample can be used
to determine blood alcohol levels.
• Chronic ethanol abuse can cause profound hepatic,
cardiovascular, pulmonary, hematologic, endocrine,
metabolic, and CNS damage.
13. Withdrawal syndrome
• When an alcohol dependent subject stops drinking,
withdrawal syndrome appears within a day. It
consists of anxiety, sweating, tachycardia, tremor,
impairment of sleep, confusion, hallucinations,
delirium tremens, convulsions and collapse.
15. Alcohol addiction
• Alcohol addiction, also known as alcoholism, is a
disease that affects people of all walks of life. Experts
have tried to pinpoint factors like genetics, sex, race,
or socioeconomics that may predispose someone to
alcohol addiction. But it has no single cause.
• Alcoholism decreases life expectancy by 10 to 15
years and impacts one in three families.
• Alcoholism is also called Alcohol Use Disorder (AUD),
appeals to the pleasure centers of the brain.
16. Alcohol addiction
• Alcoholism is associate with sensations like euphoria,
relaxation, and loss of inhibitions. This results in
cravings and dependency.
17. Risk for Alcoholism
• Genetics and family history:
• Approximately 45-65% of the liability is due to genetic
factors. Alcohol dehydrogenase 1B (ADH1B) and
Aldehyde dehydrogenase 2 ( ALDH2) are have the
strongest known affects on risk for alcoholism. The genes
including GABRA2, CHRM2, KCNJ6, and AUTS2 are also
has risk for alcoholism.
• Individuals carrying even a single copy of the
ALDH2*504K (ALDH2*2 allele; rs671) display the “Asian
flushing reaction” when they consume even small
amounts of alcohol; this includes prominent facial
flushing, tachycardia, and nausea.
Edenberg HJ, Foroud T. Genetics and alcoholism. Nat Rev Gastroenterol Hepatol. 2013;10(8):487-94.
18. Risk for Alcoholism
• Underage drinking:
• Underage drinking is a serious public health problem. The
consequences of underage drinking can affect everyone,
regardless of age or drinking status. People ages 12 to 20
drink 4.0 percent of all alcohol consumed in the United
States.
• Underage drinking poses a range of risks and negative
consequences including
– Increases the risk of alcohol problems later in life
– Increases the risk of physical and sexual assault
– Impairs judgment
– Injuries and death.
Underage Drinking. Available in https://www.niaaa.nih.gov/publications/brochures-and-fact-sheets/underage-
drinking , Last assessed on 09 May 2022
19. Risk for Alcoholism
• Underage drinking:
• Underage drinking is a serious public health problem. The
consequences of underage drinking can affect everyone,
regardless of age or drinking status. People ages 12 to 20
drink 4.0 percent of all alcohol consumed in the United
States.
• Underage drinking poses a range of risks and negative
consequences including
– Increases the risk of alcohol problems later in life
– Increases the risk of physical and sexual assault
– Impairs judgment
– Injuries and death.
Underage Drinking. Available in https://www.niaaa.nih.gov/publications/brochures-and-fact-sheets/underage-
drinking , Last assessed on 09 May 2022
20. Risk for Alcoholism
• Frequent drinking:
• Drinking too much alcohol regularly can damage
body and brain.
• NIAAA defines heavy drinking as follows:
– For men, consuming more than 4 drinks on any
day or more than 14 drinks per week
– For women, consuming more than 3 drinks on
any day or more than 7 drinks per week
https://www.niaaa.nih.gov/alcohol-health/overview-alcohol-consumption/moderate-binge-drinking, Last assessed
on 09 May 2022
21. Risk for Alcoholism
• Mental health conditions: Alcohol abuse can cause signs and
symptoms of depression, anxiety, psychosis, and antisocial
behavior, both during intoxication and during withdrawal.
• Trauma history: The onset of trauma precedes the onset of
alcohol dependence.
• Male gender: Men are more likely than women to become
addicted to alcohol. The 2018 National Survey on Drug Use and
Health found 9.2 million men and 5.3 million women in the U.S.
had an alcohol use disorder.
• Social factors: Social and family customs, culture, poor parental
support, and peer pressure can play roles in alcohol addiction.
https://www.webmd.com/connect-to-care/addiction-treatment-recovery/alcohol/what-causes-alcohol-addiction
https://pubs.niaaa.nih.gov/publications/arh26-2/90-98.htm, Last assessed on 09 May 2022
23. Alcohol tolerance
• Alcohol tolerance refers to the bodily responses to
the functional effects of ethanol in alcoholic
beverages.
Underage Drinking. Available in https://www.niaaa.nih.gov/publications/brochures-and-fact-sheets/underage-
drinking , Last assessed on 09 May 2022
24. Alcohol tolerance
• Alcohol tolerance refers to the bodily responses to
the functional effects of ethanol in alcoholic
beverages.
• Alcohol tolerance can be classified as
– Metabolic tolerance
– Functional tolerance
25. Alcohol tolerance
• Metabolic tolerance occurs when a specific group of liver
enzymes is activated after a period of chronic drinking
and results in more rapid elimination of alcohol from the
body.
• Functional tolerance is when the brain functions of
drinkers adapt to compensate for the disruption that
alcohol causes in their behavior and their bodily
functions. Functional tolerance can result in dependence.
Different types of functional tolerance are
– Acute Tolerance
– Environment-Dependent Tolerance
– Environment-Independent Tolerance
– Learned Tolerance
https://alcoholrehabhelp.org/addiction/tolerance/ Available in 09 may 2022
26. Alcohol tolerance
• Acute Tolerance: Alcohol tolerance that occurs in a single
drinking session is called acute tolerance.
• Environment-Dependent Tolerance: Regularly drinking in
the same place may cause you to develop tolerance. This
type of alcohol tolerance is common in social drinkers.
• Environment-Independent Tolerance: Drinking every day
can lead to tolerance regardless of environmental
influences. It usually occurs in people with alcohol use
disorders (AUDs).
• Learned Tolerance: This is called behaviorally augmented
tolerance. Alcohol tolerance can also be accelerated by
practicing a task while under the influence of alcohol.
https://alcoholrehabhelp.org/addiction/tolerance/ Available in 09 may 2022
28. Alcohol dependence and its features
• Alcohol dependence is psychiatric diagnosis in which an
individual is physically or psychologically dependent upon
alcohol.
• Prolonged excessive alcohol consumption sets in motion a
host of neuroadaptive changes in the brain’s reward and
stress systems. The development of alcohol dependence is
thought to reflect an allostatic state. In the dependent
individual, this allostatic state is fueled by progressive
dysregulation of the brain’s reward and stress systems
beyond their normal homeostatic limits. These
neuroadaptive changes associated with dependence and
withdrawal.
Becker HC. Alcohol dependence, withdrawal, and relapse. Alcohol Res Health. 2008;31(4):348-61.
29. Alcohol dependence features
• CANT STOP
– Compulsion to drink alcohol with stereotyped drinking
pattern
– Aware of physical/psychological harm but continues to
drink
– Neglect of other activities e.g. self-care, social,
occupational
– Tolerance to alcohol
– Stopping drinking leads to withdrawal symptoms
– Time pre-occupied with alcohol increases
– Out of control use of alcohol
– Persistent, futile attempts to cut down
https://psychmnemonics.wordpress.com/2014/11/20/alcohol-dependence-features/ [09 May 2022]
31. Rehabilitation for alcohol addiction
• There are many different options for treatment.
• There are both inpatient and outpatient centers, and each
alcohol rehab facility has their own programs designed for
treatment.
• One of the most crucial steps in attending an alcohol rehab
center is the detoxification process. During this stage, many
people are learning to live without alcohol for the first time in
a long time.
• Detoxication can be dangerous, and an alcoholic’s body can go
into shock when they are flushing the toxins out of their body.
• Rehab professionals are trained to treat individuals as they go
through the process of detoxication and withdrawal, and their
expertise can make the difference between life and death.
32. Rehabilitation for alcohol addiction
Drugs for alcohol addiction:
• Disulfiram, Naltrexone, Acamprosate
• Disulfiram blocks aldehyde dehydrogenase and metabolism of
ethanol, which results accumulation of acetaldehyde.
Accumulation of acetaldehyde produces an unpleasant flushing
reaction when alcohol is ingested.
• Naltrexone (adjunct therapy) an opioid receptor antagonist
that blocks the reinforcing properties of alcohol. Chronic
administration of naltrexone resulted in a decreased rate of
relapse to alcohol drinking.
• Acamprosate (attenuate one of the mechanisms that lead to
relapse) is a competitive inhibitor of the N-methyl-D-aspartate
(NMDA) type glutamate receptor.
Notas do Editor
Korsakoff's psychosis (or syndrome) is a severe, diencephalic amnesia caused by thiamine deficiency
Carminative: An agent that prevents or relieves flatulence (gas in the gastrointestinal tract)
Korsakoff's psychosis (or syndrome) is a severe, diencephalic amnesia caused by thiamine deficiency
Korsakoff's psychosis (or syndrome) is a severe, diencephalic amnesia caused by thiamine deficiency