Miscellaneous substances - Alcohol

Alcohol

Drug group - Miscellaneous substances

Drug effects
Alcohol is a depressant drug. In small quantities it reduces anxiety and induces feelings of pleasure and relaxation. Consumed in larger quantities it leads to loss of co-ordination, alteration in thought processes and social interaction, and, in some cases, aggression. Drinking large amounts can lead to nausea, vomiting, coma and death. Individuals differ in their response to alcohol and this will depend on rate of absorption, distribution in the body and rate of metabolism.

Dependency
During periods of heavy drinking, the body develops a tolerance to alcohol and this can lead to the development of physical dependence. There is now substantial evidence that some individuals have a genetic predisposition to develop alcohol dependence.

Withdrawal
Abrupt withdrawal of alcohol when there is dependency results in the development of delirium tremens, characterised by hallucinations and seizure.

Health effects
Light and moderate drinkers are at lower risk of ischaemic stroke (blocked cerebral artery) and coronary heart disease. Binge drinking is associated with increased risk of both ischaemic and haemorrhagic stroke. Heavy short and long term drinking is associated with increased risk of haemorrhagic stroke. Heavy drinking is also associated with gastritis, ulcers, high blood pressure, sexual difficulties, cirrhosis of the liver, cancer of the throat mouth and gullet, muscle disease, peripheral nerve damage and brain damage. Mental health problems include personality changes, fits, depression and suicide.

Overdose risk
Drinking large quantities of alcohol can lead to coma and death. Inhalation of vomit while asleep or unconscious also represents a significant risk following intoxication. Risks are increased if alcohol is used in combination with other drugs such as opiates, benzodiazepines and barbiturates.

Risk in pregnancy
Drinking 1 or 2 units of alcohol a day once or twice a week during pregnancy is not thought to pose any risk to the foetus, although some doctors may advise pregnant women not to drink at all. Chronic heavy drinking in pregnancy can lead to the development of Foetal Alcohol Syndrome, which is characterised by growth deficiency, distinctive facial features and learning difficulties and a number of alcohol-related birth defects (ARBD). The threshold for any alcohol-related harm in the foetus is thought to be about 4 -5 drinks per day which is well above the daily recommended limit (see below).

Alcohol content
Different alcoholic drinks contain different amounts of alcohol. Alcohol is measured in units or as Alcohol by Volume (ABV). Ordinary beers are about 4% ABV, wine is on average 10-13% ABV and unmixed spirits are 40% ABV.

Drink Units:

1 pub measure of spirits - 1 units
1 small glass of wine - 1 units
1 pint low alcohol beer - 0.5 units
1 pint beer - 2 units
1 bottle super or special lager - 2.5 units
1 pint strong lager - 3 units
1 can super or special lager - 4 units
1 75 CL bottle wine - 8-10 units
1 75 CL bottle of spirits (whisky, gin, vodka) - 30 units

Sensible drinking
For men who drink 3 or 4 units a day there is no significant health risk. Consistently drinking 4 or more units a day is not advised. For women drinking 2 or 3 units a day there is no significant health risk. Consistently drinking 3 or more units a day is not advised. For men over 40 years of age and women past the menopause drinking 1 or 2 units a day helps protect against coronary heart disease.

Legal status
It is against the law:

to give alcohol to a child under 5 years unless under medical supervision
for a young person under 14 years (18 years in Northern Ireland) to be in a bar unless the licensee has a children's certificate
for a person under 18 years to drink alcohol in a bar
for a licensee knowingly to sell alcohol to a person under 18 years. However, young people 16 years or older can buy beer or cider with a meal in a pub or hotel
to drive with more than 80mg of alcohol in every 100mls of blood
in some areas, there are also local by-laws that ban drinking in the street