出典(authority):フリー百科事典『ウィキペディア(Wikipedia)』「2013/04/13 12:33:34」(JST)
Alcohol intoxication | |
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Classification and external resources | |
The Drunkenness of Noah by Michelangelo |
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ICD-10 | F10.0, T51 |
ICD-9 | 305.0, 980 |
MedlinePlus | 002644 |
MeSH | D000435 |
Alcohol intoxication (also known as drunkenness or inebriation) is a physiological state induced by the consumption of alcohol.
Problems accumulate when alcohol builds up in the bloodstream faster than it can be metabolized by the liver. Some effects of alcohol intoxication are central to alcohol's desirability as a beverage and its history as the world's most widespread recreational drug. Common effects are euphoria and lowered social inhibitions. Other effects are unpleasant or dangerous because alcohol affects many different areas of the body at once and may cause progressive, long-term harm when consumed in excess.
Common symptoms of alcohol intoxication include slurred speech, euphoria, impaired balance, loss of muscle coordination (ataxia), flushed face, dehydration, vomiting, reddened eyes, reduced inhibitions, and erratic behavior. Sufficiently high levels of blood-borne alcohol will cause coma and death from the depressive effects of alcohol upon the central nervous system. "Acute alcohol poisoning" is a related medical term used to indicate a dangerously high concentration of alcohol in the blood, high enough to induce coma or respiratory depression. It is considered a medical emergency. The term is mostly used by health care providers. Toxicologists use the term “alcohol intoxication” to discriminate between alcohol and other toxins.
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Alcohol is metabolized by a normal liver at the rate of about one ounce (one two-ounce shot of spirits, a normal beer, a regular sized glass of wine) every 90 minutes.[citation needed] An "abnormal" liver with conditions such as hepatitis, cirrhosis, gall bladder disease, and cancer will have a slower rate of metabolism.
Ethanol is metabolised to acetaldehyde by alcohol dehydrogenase (ADH), which is found in many tissues, including the gastric mucosa. Acetaldehyde is metabolised to acetate by acetaldehyde dehydrogenase (ALDH), which is predominantly found in liver mitochondria. Acetate is used by the muscle cells to produce acetyl-CoA using the enzyme acetyl-CoA synthetase, and the acetyl-CoA is then used in the citric acid cycle.[1] It takes roughly 90 minutes for a healthy liver to metabolize a single ounce, approximately one hour per standard unit.
Ethanol's acute effects are largely due to its nature as a central nervous system depressant, and are dependent on blood alcohol concentrations:
As drinking increases, people become sleepy, or fall into a stupor. After a very high level of consumption, the respiratory system becomes depressed and the person will stop breathing. The most important thing for people who witness someone "passing out" from too much alcohol is to get them emergency medical treatment. Comatose patients may aspirate their vomit (resulting in vomitus in the lungs, which may cause "drowning" and later pneumonia if survived). CNS depression and impaired motor co-ordination along with poor judgement increases the likelihood of accidental injury occurring.[3] It is estimated that about one third of alcohol-related deaths are due to accidents (32%), and another 14% are from intentional injury.[4]
In addition to respiratory failure and accidents caused by effects on the central nervous system, alcohol causes significant metabolic derangements. Hypoglycaemia occurs due to ethanol's inhibition of gluconeogenesis, especially in children, and may cause lactic acidosis, ketoacidosis and acute renal failure. Metabolic acidosis is compounded by respiratory failure. Patients may also present with hypothermia.
In the past, alcohol was believed to be a non-specific pharmacological agent affecting many neurotransmitter systems in the brain.[5] However, molecular pharmacology studies have shown that alcohol has only a few primary targets. In some systems these effects are facilitatory and in others inhibitory.
Among the neurotransmitter systems with enhanced functions are: GABAA,[6] 5-HT3 receptor agonism[7] (responsible for GABAergic (GABAA receptor PAM), glycinergic, and cholinergic effects), nicotinic acetylcholine receptors.[8]
Among those that are inhibited are: NMDA,[7] dihydropyridine-sensitive L-type Ca2+ channels[9] and G-protein-activated inwardly rectifying K+ channels.[10]
The result of these direct effects is a wave of further indirect effects involving a variety of other neurotransmitter and neuropeptide systems, leading finally to the behavioural or symptomatic effects of alcohol intoxication.[5]
Definitive diagnosis relies on a blood test for alcohol, usually performed as part of a toxicology screen.
Law enforcement officers often use breathalyzer units and field sobriety tests as more convenient and rapid alternatives to blood tests. The reliability of field sobriety tests is somewhat questionable, although they are commonly used in various jurisdictions.[citation needed]
There are also various models of breathalyzer units that are available for consumer use. Because these may have varying reliability and may produce different results than the tests used for law-enforcement purposes, the results from such devices should be conservatively interpreted.
Many informal intoxication tests exist, which are generally unreliable and not recommended as deterrents to excessive intoxication or as indicators of the safety of activities such as motor vehicle driving, heavy equipment operation, machine tool use, etc.
For determining whether someone is intoxicated by alcohol by some means other than a blood-alcohol test, it is necessary to rule out other conditions such as hypoglycemia, stroke, usage of other intoxicants, mental health issues, and so on. It is best if their behavior has been observed while the subject is sober to establish a baseline. Several well-known criteria can be used to establish a probable diagnosis. For a physician in the acute treatment setting, acute alcohol intoxication can mimic other acute neurological disorders, or is frequently combined with other recreational drugs that complicate diagnosis and treatment.
The signs and symptoms of acute alcohol poisoning include:
Acute alcohol poisoning is a medical emergency due to the risk of death from respiratory depression and/or inhalation of vomit if emesis occurs while the patient is unconscious and unresponsive. Emergency treatment for acute alcohol poisoning strives to stabilize the patient and maintain a patent airway and respiration, while waiting for the alcohol to metabolize:[13] Also:
Additional medication may be indicated for treatment of nausea, tremor, and anxiety.
A normal liver detoxifies the blood of alcohol over a period of time that depends on the initial level and the patient's overall physical condition. An abnormal liver will take longer but still succeed, provided the alcohol does not cause liver failure.[14]
People who have been drinking heavily for several days or weeks may have withdrawal symptoms after the acute intoxication has subsided.[15]
A person who consumes a dangerous amount of alcohol persistently can develop memory blackouts and idiosyncratic intoxication or pathological drunkenness symptoms.[16]
Long-term persistent consumption of excessive amounts of alcohol can cause liver damage and have other deleterious health effects.
Alcohol intoxication is a risk factor in some cases of catastrophic injury, particularly for unsupervised recreational activity. A study in the province of Ontario in Canada based on epidemiological data from 1986, 1989, 1992, and 1995 states that 79.2% of the 2,154 catastrophic injuries recorded for the study were preventable, of which 346 involved alcohol consumption.[17] The activities most commonly associated with alcohol-related catastrophic injury were snowmobiling (124), fishing (41), diving (40), boating (31) and canoeing (7), swimming (31), riding an all-terrain vehicle (24), and cycling (23).[17] These events are often associated with unsupervised young males, often inexperienced in the activity, and many result in drowning.[17]
Laws on drunkenness vary. In the United States, it is a criminal offense for a person to be drunk while driving a motorized vehicle, except in Wisconsin, where it is only a forfeiture for the first offense.[18] It is also a criminal offense to fly an aircraft or (in some American states) to assemble or operate an amusement park ride while drunk.[19] Similar laws also exist in the United Kingdom and most other countries.
In some countries, it is also an offense to serve alcohol to an already intoxicated person,[20] and often alcohol can only be sold by persons qualified to serve responsibly through alcohol server training.
The blood alcohol content (BAC) for legal operation of a vehicle is typically measured as a percentage of a unit volume of blood. This percentage ranges from 0.00% in Romania and the United Arab Emirates; to 0.05% in Australia, South Africa, and Germany; to 0.08% in the United Kingdom, the United States, and New Zealand.[21]
Additionally, the United States Federal Aviation Administration prohibits crew members from performing their duties with a BAC greater than 0.04% within eight hours of consuming an alcoholic beverage, or while under the influence of alcohol.[22][23]
In the United States, the United Kingdom, and Australia, people can be arrested for public intoxication, which the law may call "being drunk and disorderly" or "being drunk and incapable."[24]
In some jurisdictions, alcohol intoxication may be a defense against some criminal charges, or a mitigating factor in sentencing.
Some religious groups permit the consumption of alcohol. Some permit consumption but prohibit intoxication, while others prohibit alcohol consumption altogether. In the Qur'an,[25][26][27] there is a prohibition on the consumption of grape-based alcoholic beverages, and intoxication is considered as an abomination in the Hadith. Islamic schools of law (Madh'hab) have interpreted this as a strict prohibition of the consumption of all types of alcohol and declared it to be haraam ("sinful"), although other uses may be permitted.[28]
Some Protestant Christian denominations prohibit the drinking of alcohol[29] based upon Biblical passages which condemn drunkenness (such as Proverbs 23:21,[30] Isaiah 28:1,[31] Habakkuk 2:15[32]), but others allow moderate use of alcohol.[33] In some Christian groups, wine is part of the rite of communion. In The Church of Jesus Christ of Latter-day Saints, alcohol consumption is forbidden,[34] and teetotalism has become a distinguishing feature of its members. Jehovah's Witnesses allow moderate alcohol consumption amongst its members.
In Buddhism, the consumption of intoxicants is generally discouraged for both monastics and lay followers. Many followers of Buddhism observe a code of conduct known as the Five Precepts, of which the fifth precept is an undertaking to refrain from the consumption of intoxicating substances (except for medical reasons). In the Bodhisattva Vows of the Brahma Net Sutra, observed by some monastic communities and some lay followers, distribution of intoxicants is likewise discouraged as well as consumption.
In Vaishnavism, specifically Gaudiya Vaishnavism, one of the four regulative principles forbids the taking of intoxicants, including alcohol.
Wikisource has the text of the 1911 Encyclopædia Britannica article Drunkenness. |
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(help). On Alcohol Use In America. sbc.net. |title=
(help). Alcohol. lcms.org.
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リンク元 | 「アルコール中毒」「alcohol addiction」「alcohol poisoning」「drunkenness」 |
関連記事 | 「alcoholic」「alcoholics」「alcohol」「intoxication」 |
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