alcohol slides

Ethyl Alcohol and the Inhalants of Abuse

Introduction

  • Exploration of whether there is a natural drive to become intoxicated.

  • Discussion about societal perceptions of intoxicated individuals.

Ethyl Alcohol (Ethanol) Overview

  • Ethyl alcohol, commonly referred to as ethanol, is a widely consumed psychoactive substance.

  • Only caffeine is more widely used compared to alcohol.

Misconceptions and Cultural References

  • Use of various informal slang references related to alcohol:

    • Pabst, Ghetto, Blaster, cuntscumb, PATE, ABSOLUT, KON, MALIBU, CARSOANE.

Dangers of Smoking Alcohol

  • Smoking alcohol is deemed an unwise practice for several reasons:

    • Alcohol is poisonous to the lungs and detrimental to the nasal passages.

    • Rapid onset of alcohol poisoning occurs because the alcohol is vaporized directly into the bloodstream, hindering the body's ability to expel excess via vomiting.

    • Difficulties in measuring actual intake as vaporized alcohol volume is not quantifiable without scientific equipment.

    • Particularly harmful for asthmatics or individuals with lung infections, exacerbating their conditions.

  • Emphasizes the importance of understanding kinetics in how alcohol is processed in the body.

Binge Drinking

  • Definition of binge drinking:

    • Old Definition: Drinking excessively over a period of more than two days, typically without engaging in other activities.

    • New Definition: Consuming 5 or more drinks in one sitting for males, and 4 or more drinks for females.

    • Personal Definition: Drinking excessively in one sitting leading to commonly recognized negative consequences (e.g., vomiting, risky behaviors, violence, academic/work issues).

Safe Drinking Tips

  • Suggestions for safer drinking practices include:

    • Setting personal limits and adhering to them.

    • Consuming no more than 2 drinks in 3 hours.

    • Alternating each alcoholic drink with a non-alcoholic beverage.

    • Consuming food before and during drinking sessions.

    • Taking into account individual health factors such as age, body weight, and underlying health issues.

  • The Canadian Centre on Substance Use and Addiction promotes moderation in drinking to support healthier lifestyles.

Health Risks Associated with Alcohol Metabolism

  • Acetaldehyde and Reactive Oxygen Species (ROS) from alcohol metabolism are capable of damaging DNA.

  • Inflammation caused by alcohol can result in cellular damage and elevated cancer risks.

  • Important nutrients such as vitamins and folic acid are crucial for the cellular machinery that repairs DNA damage due to alcohol metabolism.

  • Alcohol usage increases absorption of harmful substances in the mouth and throat, as well as elevating hormone levels (like estrogen) leading to higher breast cancer risks.

  • Alcohol is calorie-dense, contributing to unwanted weight gain, which is a risk factor for cancer.

Historical Context of Alcohol in Canada

  • 1864: The Drunkin Act allowed local municipalities to ban liquor sales through majority votes.

  • 1878: The Canada Temperance Act passed, extending local option to the whole Dominion.

  • 1898: A national plebiscite aimed to evaluate prohibition but was deemed inconclusive due to lack of majority support, particularly from Quebec.

  • Prohibition Era: Prohibitory laws were enacted sporadically across provinces beginning in 1901, seen as a patriotic duty during the First World War.

  • Quebec's Resistance: Rejected prohibition as early as 1919, while profiting from tourism related to liquor sales.

Fermentation Process

  • The process of fermentation can be summarized by the following:

    • Ingredients: Sugar, water, and yeast.

    • Yeast metabolizes sugar into ethanol and carbon dioxide (CO2).

    • Determining alcohol type depends on the sugar source.

    • Yeast dies off at about 13-14% alcohol content.

    • The anaerobic condition allows conversion of glucose to pyruvic acid through glycolysis, followed by the conversion of pyruvic acid into ethanol.

Other Fermentation Products

  • Besides ethanol, some organisms convert pyruvic acid into lactic acid, causing stiffness in muscles during anaerobic conditions.

  • After cessation of strenuous activity, lactic acid is converted back to ATP once aerobic conditions resume.

Alcohol Metabolism: A Three-step Process

  1. Alcohol Dehydrogenase (ADH): Converts alcohol to acetaldehyde, requiring the coenzyme Nicotinamide Adenine Dinucleotide (NAD); NAD availability limits this step.

  2. Aldehyde Dehydrogenase: Converts acetaldehyde to acetic acid.

  3. Acetic Acid Conversion: Breaks down into carbon dioxide and water.

    • Breakdown statistics: 95% metabolized by ADH, 5% excreted unchanged, predominantly through the lungs, 85% metabolized in the liver, and 15% in the stomach lining.

Distillation Process

  • Distillation involves heating a fermented solution:

    • Alcohol evaporation occurs due to its lower boiling point relative to water.

    • Vapor is collected to create a liquid with a higher alcohol content.

    • This process can be repeated until desired alcohol concentration is achieved.

    • Moonshine quality is assessed by burning a teaspoon of the alcohol—only a drop of water should remain post-burn.

Measuring Alcohol Content

  • Proof System origins are tied to historical methods of testing rum alcohol by the British Navy.

    • If rum ignited when mixed with gunpowder, it signified at least 50% alcohol content.

  • Variance in proof systems:

    • US System: Expresses alcohol by volume; 100 proof implies 50% alcohol by volume.

    • British System: Indicates alcohol by weight; 100 proof equates to about 48.24% weight (approximately 57.06% by volume).

  • For practical measurements: Alcohol has a specific gravity of 79% compared to water for the same volume.

Alcohol Pharmacokinetics

Absorption

  • Alcohol is absorbed completely through the gastrointestinal (GI) tract, primarily in the intestines.

  • Peak blood concentration occurs within 30-60 minutes post-consumption:

    • On empty stomach: 20% absorbed in the stomach and 80% in the upper intestine.

    • On full stomach: Absorption is significantly reduced due to the activity of gastric alcohol dehydrogenase.

Distribution

  • Alcohol is evenly distributed throughout the body and can easily cross both the blood-brain barrier (BBB) and placental barriers.

  • Faster gastric emptying increases blood alcohol concentration (BAC) by allowing less time for first-pass metabolism.

Sex Differences in Alcohol Metabolism

  • Women experience higher BAC compared to men when consuming the same amount of alcohol, even after body weight adjustments.

  • Gastric Metabolism: Women possess 50% less gastric metabolism, resulting in higher BAC by approximately 7%.

  • Men have more muscle mass and blood flow, diluting alcohol more effectively whereas higher fat content in women results in more alcohol remaining in blood plasma.

Kinetic Differences in Alcohol Metabolism

  • Alcohol metabolism operates on a zero-order kinetic basis:

    • The metabolism rate remains constant regardless of blood concentration levels, differing from first-order kinetics seen in most drugs where metabolic rates are concentration-dependent.

Rate of Alcohol Metabolism

  • The average person metabolizes 6-8 grams of alcohol (~100mg/hour/kg) per hour.

  • Generally, metabolism estimates:

    • One hour to metabolize the equivalent of 1 ounce of whiskey, 4oz of wine, or 12oz of beer.

Short-term Effects of Alcohol Consumption

  • Light to Moderate Drinking may elicit:

    • Loss of inhibitions, relaxation, altered judgment, buzz sensation, and loss of coordination.

  • Moderate to Large Consumption can result in adverse effects including:

    • Decreased heart rate, slower respiration, reduced pain sensation, memory impairments, sleep disturbances, sexual dysfunction, and vision problems.

Pharmacodynamics: Effects of Alcohol on the CNS

  • Identifying the precise mechanism through which alcohol acts on the brain is complex:

    • Initial theories suggested alcohol perturbed neuronal membranes, causing non-specific depressant effects.

    • Recent discoveries show alcohol may alter neurotransmitter systems, specifically:

    • Disturbing both glutamate (antagonist) and GABA systems (agonist).

    • Impacting intracellular processes, cyclic AMP pathways, calcium ion channels, and endocannabinoid systems.

Actions of the brain’s Glutamate System in Presence of Alcohol

  • Ethanol inhibits activity of the N-Methyl-D-Aspartate Receptors (NMDARs) and α-amino-3-hydroxy-5-methylisoxazole-4-proprionic Acid Receptors (AMPARs), which leads to reduced cation entry and diminished neuronal activity.

Role of GABA in Alcohol’s Effect

  • Alcohol amplifies the inhibitory effects at specific GABA-A receptor subtypes, resulting in sedation and muscle relaxation.

  • Positive allosteric modulators, such as alcohol, enhance GABA binding to receptors, leading to increased chloride ion flow, with behavioral consequences including sedation and inhibition of cognitive and motor functions.

  • Chronic alcohol use has potential genetic effects that alter intracellular mRNA and gene expression.

Alcoholism as a Dependency

  • Alcoholism is characterized as an uncontrollable use of alcohol driven often by psychological factors:

    • Cholecystokinin (CCK) is linked with both anxiety and alcoholism, influencing dopamine release in brain's reward pathways.

Neurobiology of Alcoholism and Treatment Options

  • Distinction between Alcohol Use Disorder (AUD) and alcoholism is emphasized, with various symptoms:

    • Craving, loss of control, physical dependence (withdrawal symptoms), and tolerance.

  • DSM-5 criteria revision and further classification for diagnosing AUD.

Treatment Approaches:

  • Counseling & Behavioral Therapy: Individual therapy, group therapies, and community reinforcement approaches.

  • Pharmacotherapy:

    • Disulfiram (Antabuse): Causes adverse responses when alcohol is consumed; it inhibits aldehyde dehydrogenase.

    • Naltrexone: Opioid receptor antagonist that helps reduce cravings.

    • Newer approaches look to target neuropeptides and receptor systems for promising outcomes.

Conclusion

  • Ongoing research into the genetics of alcohol consumption suggests heritability plays a role in risk for alcohol use disorders, while lifestyle factors also influence outcomes.

  • Emphasis on the need for a range of comprehensive treatments, including pharmacological and therapeutic avenues for effective management of alcohol dependence and abuse.