Dental Alcohol

Pharmacologic Properties of Alcohol

• Pharmacologic properties of alcohol include sedation, anesthesia, and death due to respiratory depression
• Alcohol is a central nervous system depressant, causing decreased activity and depressing nerve conduction
• It is a vasodilator, causing increased blood flow to the skin, and is a diuretic due to inhibition of vasopressin

Effects on Blood Vessels

• Alcohol causes vasodilation, leading to increased blood flow to the skin and decreased blood pressure

Lethal Respiratory Depression

• Lethal respiratory depression occurs at a blood alcohol concentration of 0.35-0.40%

Nerve Conduction

• Alcohol slows down nerve conduction velocity and increases the refractory period

Effects on Cell Cytoplasm

• Alcohol causes disruption of cell membranes, leading to increased permeability and altered cell function

Effects on Mucosa and Skin

• Alcohol causes irritation and inflammation of mucosa and skin surfaces, leading to increased permeability and susceptibility to infection

Food and Absorption

• Presence of food in the stomach slows down alcohol absorption, but does not affect the overall amount absorbed

Permeable Body Compartments

• Body compartments very permeable to alcohol include the brain, liver, and kidneys

Rate of Absorption

• Rate of alcohol absorption is the fastest when the stomach is empty

Barriers to Absorption

• Barriers highly permeable to alcohol include the blood-brain barrier and the placenta

Body System and Metabolism

• The liver is the primary organ responsible for the metabolism of alcohol, and the body system receiving the highest proportion of alcohol is the circulatory system

Metabolism and Elimination

• 90-95% of alcohol is metabolized, and the remaining 5-10% is excreted unchanged through the kidneys, lungs, and sweat

Metabolic Kinetics

• Alcohol metabolism follows zero-order kinetics, meaning that the rate of metabolism is constant and independent of concentration

Enzyme Systems

• The enzyme systems responsible for breaking down alcohol in the liver are the alcohol dehydrogenase (ADH) and the microsomal ethanol oxidizing system (MEOS)

Factors Affecting Metabolism

• Factors affecting the rate of alcohol metabolism include gender, body weight, and food intake

Average Metabolism Rate

• The average person can metabolize 0.01-0.02% of blood alcohol concentration per hour

Microsomal Ethanol Oxidizing System (MEOS)

• MEOS is an additional metabolic system that becomes active in chronic alcoholics or when large quantities of alcohol are ingested
• MEOS uses the coenzyme NADPH and can be induced by chronic alcohol consumption, resulting in increased tolerance

Induction of MEOS

• MEOS can be induced by chronic alcohol consumption, resulting in increased tolerance

Rate of Metabolism and Consumption

• The rate of alcohol metabolism increases with increased alcohol consumption

Central Nervous System

• Alcohol inhibits the GABA-inhibitory neurotransmitter system and enhances the GABA-stimulatory system
• It also inhibits the voltage-gated calcium channels in the central nervous system

Cardiovascular Effects

• Cardiovascular effects of alcohol consumption include decreased blood pressure, increased heart rate, and vasodilation

Gastrointestinal Effects

• Gastrointestinal effects of alcohol consumption include increased acid production, inflammation, and damage to the liver

Metabolic Effects

• Metabolic effects of alcohol on the body include increased glucose production, decreased fat metabolism, and increased lipogenesis

Hormonal Effects

• Hormonal effects of alcohol include inhibition of vasopressin, leading to increased diuresis, and stimulation of the anterior pituitary gland

Hormone Regulation

• Chronic alcohol consumption can lead to feminization of males due to inhibition of the hormone dihydrotestosterone

Drug Interactions

• Alcohol interacts with certain drugs, such as oral hypoglycemics, and can affect their metabolism and efficacy

Legal Blood-Alcohol Limits

• The legal blood-alcohol limit for driving in the US is 0.08%, and the limit for commercial drivers is 0.04%
• The legal limit for pilots of aircraft in the US is 0.04%
• The BAC level considered illegal for drivers under the age of 21 in all US states is 0.02%

Testing Equipment

• Criticisms of the testing equipment for alcohol measurement include concerns about accuracy and reliability

Chronic Alcoholism

• Nutrient deficiencies commonly associated with chronic alcoholism include thiamine deficiency and Wernicke-Korsakoff syndrome
• Chronic alcohol consumption can lead to weight loss and decreased muscle mass
• It can also lead to disorientation, confabulation, peripheral neuritis, and amnesia

Disulfiram (Antabuse)

• Disulfiram (Antabuse) inhibits the enzyme aldehyde dehydrogenase and causes the accumulation of acetaldehyde, leading to unpleasant symptoms when combined with alcohol
• It is used in the treatment of chronic alcoholism to deter alcohol consumption

Naltrexone (ReVia)

• Naltrexone (ReVia) is used in the treatment of opioid and alcohol dependence

Ro15-4513

• Ro15-4513 is a benzodiazepine receptor antagonist that can block the effects of ethanol
• It is structurally related to benzodiazepines and can induce anxiety and withdrawal symptoms
• Limitations of Ro15-4513 include its short half-life and inability to block the effects of ethanol at high concentrations