Module 2c Alcohol, Tobacco and caffiene use no voiceover

Drugs in Society

• Focus on Module 2c: Caffeine, Alcohol, & Tobacco

• Main substances discussed: Caffeine, Nicotine, Alcohol

Caffeine

Sources

• Present in:

  • Tea

  • Coffee

  • Cola (small amounts in decaffeinated tea & coffee)

  • Most teas contain more caffeine (weight for weight) than coffee.

Chemical Characteristics

• Chemical group: Purines

• Type: Alkaloid-like CNS stimulant

• Half-life: 1.5 to 9.5 hours (average ~5 hours)

  • Variability due to:

    • Body weight

    • Obesity

    • Altitude

    • Pregnancy

Mechanism of Action

• Acts as an adenosine receptor antagonist

  • Adenosine’s effects: lethargy, decreased heart rate, decreased GIT function

  • Caffeine’s effects:

    • Wakefulness

    • Elevated blood pressure (BP)

    • Increased heart rate (palpitations)

    • Increased gastric secretions

Withdrawal Effects

• Most common: Headaches

• Overconsumption (e.g., >8 cups/day) can lead to:

  • Cardiac rhythm abnormalities (arrhythmias)

  • Muscle tremors

  • Gastric ulceration risk

• Positive effects: Increased wakefulness beneficial for studying and long-distance driving.

• Previously banned for athletes but now removed from the banned list due to lack of performance enhancement.

Alcohol

Chemical Characteristics

• Ethanol (ETOH) defined

• Mechanism: Disrupts lipids in nerve cell membranes, altering permeability and disrupting signal transmission

• Activates dopaminergic receptors in the CNS (involved in reward, emotions, and movement)

• Classed as a CNS depressant

Effects of Alcohol

• Small amounts: Increase well-being, lower inhibitions

• Large amounts: Cause reduced coordination and potential loss of consciousness (LOC)

• Binge drinking: Can lead to coma and even death due to respiratory depression.

Addiction Potential

• Chronic alcohol use is a common serious addiction leading to:

  • Health issues

  • Job losses

  • Domestic violence

  • Relationship breakdowns

Australian Guidelines for Reduced Health Risks

• Recommendations for consumption:

  • No more than 10 standard drinks per week

  • No more than 4 standard drinks in one day

  • One to two alcohol-free days per week

  • Definition of a standard drink: 10g of alcohol

Gender Differences in Alcohol Metabolism

• Women at higher risk for lifetime damage due to:

  • Lower levels of gastric alcohol dehydrogenase

  • Higher body fat proportion

  • Less water compared to men leading to higher alcohol concentration

Problems Associated with Alcohol Consumption

• Chronic misuse: leads to health and social issues

• Hangover causes:

  • Irritation of gastric mucosa

  • Inhibition of antidiuretic hormone (ADH), leading to dehydration

Chronic Alcohol Misuse Definition

• Physical dependence leading to withdrawal symptoms within 12 hours of intake cessation.

  • Can progress to delirium tremens (DTs) with hallucinations and seizures, possibly fatal without intervention.

Physical Damage from Alcohol

• Most significant impact on the liver:

  • Inflammation

  • Cirrhosis

  • Loss of function and potential liver failure

• Other health issues:

  • Gastric ulcers

  • Pancreatitis

  • Various carcinomas

  • CNS deterioration including cerebral atrophy

  • Nutritional deficiencies, particularly thiamine (Vitamin B1)

  • Possible teratogenic effects during pregnancy.

Nicotine

Characteristics and Effects

• Addictive component of cigarettes.

• Stimulates nicotinic receptors in the brain and nervous system.

• Increases release of catecholamines (e.g., dopamine) leading to elevated blood pressure.

• Associated with appetite suppression.

• Carcinogenic substances present in cigarettes increase the risk of health issues.

• Passive smoke poses risks similar to those faced by smokers.

• Babies born to smoking mothers face risks like lower birth weights and reduced intellectual function.

Nicotine Addiction and Treatment

• Nicotine addiction can occur with as few as 10 cigarettes per day.

• Treatment strategies:

  • 80% fail on first attempt to quit smoking.

  • Nicotine replacement therapy (gum, patches, inhalers, lozenges).

  • Varenicline as a partial agonist to reduce pleasant effects of nicotine.

  • Possible need for tricyclic antidepressant therapy.

References

• Bullock, S., & Manias, E. (2022). Fundamentals of pharmacology, (9th ed.). Pearson Australia.

• Burchum, J.R. & Rosenthal, L.D. (2022). Lehne’s pharmacology for nursing care (11th ed.). Elsevier.

• NSW Department of Health (2018). Drug and alcohol withdrawal clinical practice guidelines.