Alcohol (ethanol):Pharmacological effects

Chih-Chia LaiDepartment of Pharmacology

Tzu Chi University2009-10-30

Drugs of Abuse(濫用藥物)

– 類鴉片藥物:

• Heroine, Morphine

– 中樞神經興奮劑:

• Amphetamine, Methamphetamine, MDMA, Cocaine

– 中樞神經抑制劑：

• FM2

– 中樞神經幻覺劑：

• Ketamine, LSD, Marijuana, Phencyclidine (angel dust)

– 酒精(alcohol)和尼古丁(nicotine)

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Alcohol as a drug Drug

a substance, other than food, used in the prevention, diagnosis,alleviation, treatment, or cure of disease

A substance other than food intended to affect the structure or function of the body

Alcohol is a psychoactive drug that is a CNS (central nervous system) depressant

Alcohol is the second most widely used and abused of all psychoactive drugs

Alcohol is an addictive drug Alcohol is considered as a social lubricant

Why people view alcohol as a non-drug

Alcohol is legalAdvertising and media promote drinking as

normalLarge distribution and sales of alcoholLong history of alcohol use

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Excessive alcohol (alcohol abuse) use can result in serious physical and mental problems.

Chronic excessive use that involves a compulsion to drink, increased tolerance, and withdrawal symptoms is called alcohol dependence or, alternatively, alcoholism. Tolerance: the capacity of the body to endure or become less

responsive to a substance (as a drug) or a physiological insult with repeated use or exposure

Withdrawal syndrome: the development of a substance-specific syndrome that follows the cessation of, or reduction in, intake of a psychoactive substance that the person previously used regularly

Negative Impact of Alcohol

Chronic tolerance: produced by repeated administration of ethanol over a period of days or weeks.

Acute tolerance (tachyphylaxis): that appears within minutes after a single dose.

Cross-tolerance: the resistance to one or several effects of a compound as a result of tolerance developed to a pharmacologically similar compound. It is common practice to take alcohol concurrently with other drugs

Ethanol Tolerance

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Physical dependence manifested by withdrawal reactions: hyperexcitability in mild cases, convulsion, toxic psychosis, and delirium tremens (酒狂) in severe ones. The severity of withdrawal reactions depends on dose and frequency of use, and may be life threatening.

Psychological dependence is characterized by a compulsive desire (or craving) to experience the rewarding effects of alcohol or to avoid the negative consequences of withdrawal.

Ethanol dependence

• In recent years dozens of cohort studies from all over the world have associated moderate alcohol consumption with reduced risk for cardiovascular disease, decreased overall mortality rates and other potentially improved health conditions.

Positive Impact of AlcoholModerate consumption of alcohol may prolong life span

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根據統計台灣地區十五歲以上人口之喝酒盛行率為18.83% (男：29.18%、女：7.80%)。

而在國中生的盛行率：男生為21.8%、女生為10.5%；在高中生的盛行率：男生佔百分之二十七‧ 九、女生佔百分之十七‧一，顯示青少年飲酒問題也趨於嚴重。

而台灣原住民，嚴重的嗜酒問題，一直是影響健康狀況的主要因素之一。台灣原住民酒精濫用和酒精依賴終身盛行率高達百分之二十以上，造成嚴重的健康與社會問題。

喝酒盛行率

遺傳與酒精濫用

• 酒癮者之子女，即使他們討厭父母的喝酒行為，但長大後仍有一半成為酒精濫用者。雙胞胎之研究顯示同卵雙胞胎之酒癮發生率是異卵雙胞胎的兩倍。30-50%的東方人血液中缺乏一種乙醛去氫酶（A L D H）的同類酵素。這些體質的人喝了酒，血中乙醛濃度即迅速增高，容易臉紅、心悸、胃灼熱，因此也不容易變成酒癮。

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Blood Alcohol Concentration (BAC)

The effects of alcohol on the human body depend on the amount of alcohol in the blood (blood alcohol concentration)

BAC produced depends on Presence of food in the stomach Rate of alcohol consumption Concentration of alcohol Drinker’s body composition

Almost 95% of consumed alcohol is inactivated by liver metabolism.

The liver metabolizes alcohol at a slow and constant rate and isunaffected by the amount ingested.

Thus, if one can of beer is consumed each hour, the BAC will remain constant.

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酒精之排泄(drug excretion)

酒精大部分濫用藥物

50-100 mg/dl (0.05-0.10%)Sedation, increased reaction time, subjective “high”

100-200 mg/dl (0.1-0.2%)impaired motor function, slurred speech , ataxia

200-300 mg/dl (0.2-0.3%)Emesis, stupor

300-400 mg/dl (0.3-0.4%)Coma

≥400 mg/dl (0.4%)Respiratory depression, death

Blood alcohol concentration (BAC) and clinical effects in non-tolerant individuals

CNS stimulation (disinhibition) → CNS depression Sudden death from either respiratory depression or

arrhythmias may occur when large quantities are drunk rapidly.

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Drug A : ethanol

Drug B : benzodiazepines

• 駕駛人飲酒後其吐氣所含酒精濃度超過每公升○‧二五毫克或血液中酒精濃度超過百分之○‧○五以上，不得駕車。 (道路交通安全規則第114條)

• 血液酒精濃度：吐氣每公升酒精含量0.25mg（毫克）＝血液中酒精濃度0.05％(50mg/100ml)

酒精濃度檢測

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Alcohol & CaloriesAlcoholic beverages have no vitamins,

minerals, protein, or fat – just a large amount of carbohydrates and usually caloriesAlcohol provides more calories per gram

than does carbohydrate or protein and only slightly less than does pure fat. Because it can provide many calories, the drinker’s appetite may be satisfied; as a result, he or she may not eat properly, casuing alnutrition.

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The Hangover

The symptoms: fatigue combined with nausea, upset stomach, headache, sensitivity to sound, and ill temperThese symptoms are usually most severe

many hours after drinking, when little or no alcohol remains in the body.No simple explanation exists for what

causes the hangover.

Effects of Alcohol on Organ Systems and Bodily Functions

• Brain and nervous system• Liver• Digestive system• Blood• Cardiovascular system• Sexual organs• Endocrine system• Kidneys

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• Alcohol causes a spectrum of liver injury that can progress from fatty liver to alcoholic hepatitis(often considered an intermediate stage) to cirrhosis.

• As little as 20 g of alcohol in women or 60 g in men can cause serious liver damage when consumed daily for several years. Consuming more than 60 g/day for 2 to 4 wk produces fatty liver even in otherwise healthy men; 80 g/day may lead to alcoholic hepatitis; and 160 g/day over a decade can lead to cirrhosis.

The effects of Alcohol on Liver

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The National Institute on Alcohol Abuse and Alcoholism defines moderate alcohol consumption as “no more than two standard drinks per day for most men and no more than one standard drink per day for most women.” A standard drink contains 12 g of alcohol.

It have suggested that one to two standard drinks per day is associated with reduced risk of coronary artery disease.

24 g alcohol per day (two drinks) reduced the risk of ischemic stroke and total stroke.

American Heart Association/American College of Cardiology science advisories conclude that in the absence of proof of causality, the use of alcohol as a cardioprotective strategy is not recommended.

The cardiovascular effects of Alcohol: the Good

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The adverse effects of immoderate alcohol consumption on the cardiovascular system include cardiomyopathy, hypertension, cardiac arrhythmias, and stroke.

Alcoholic cardiomyopathy generally occurs after long-term, heavy drinking (more than six standard drinks per day for longer than five years).

Studies show an association between long-term alcohol consumption of 30 to 60 g (three to five drinks) or more per day and higher systolic and diastolic blood pressures

60 g or more alcohol per day per day increased the risk of ischemic stroke and total stroke.

Heavy, long-term drinking and binge drinking also are associated with atrial and ventricular arrhythmias, some nonspecific electrocardiographic changes, and sudden cardiac death

The cardiovascular effects of Alcohol: the Bad

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The following dialogues from Shakespeare describe some of the effects of alcohol.Macbeth (Act 2, scene 3):

Macduff: What three things does drink provoke?Porter: Marry, sir, nose-painting, sleep, and urine.

Leachery, sir, it provokes, and unprovokes;It provokes the desire, but it takes away theperformance.

Effects of Alcohol on Sexual Organs

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Alcohol and Pregnancy

Moderate to excessive drinking during pregnancy can result in – Spontaneous abortion– Damage to fetus (fetal alcohol syndrome, FAS)

• Damage dose-related• A safe lower level of alcohol consumption has

not been established for pregnant women

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Fetal alcohol syndrome (FAS)

Facial abnormalities, where there is an increased distance between the inner corners of the eyes, and a thin upper lip.

Mild to severe mental retardation resulting in learning difficulties.

Low birth weight and height that persists through early childhood.

Abnormalities of the heart and other organs.

濫用藥物之毒性作用

+++Liver disease,Fetal alcohol syndrome,Life-expectancy decreasedby 10 yrs,

Contributes to highwayFatalities

+++TremorNauseaSweatingHypertensionSeizureDelirium

Life-threatening

Stimulant at lowdoses includingeuphoria and increasedtalkativeness

Depressantat high doses producingataxia, slurredspeech, decreasedmotorSkills

++Ethanol酒精

+++Neurotoxicity,Flashbacks,Toxic psychosis,PCP can be lethal

-Distortion of perception,mood,and thought

Severe CNS depression

+LSD

PCP

中樞神經幻覺劑

不良後果戒斷徵候急性作用濫用潛力濫用藥物藥物類別

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