DRUGS OF ABUSE-PART-1-ALCOHOL

ALCOHOL-A DRUG OF ABUSE

Alcohol a technical term in organic chemistry can be used for a large variety of substances that have some specific chemical nature or molecular structure.

All alcohols are having in their chemical formula a specific -OH- group which when reacting with an acid to give a product known as ester instead of salt. This -OH- is known as an alcoholic -OH-.

Where an alkaline Hydroxyl (-OH)group found in inorganic chemistry differs from an alcoholic hydroxyl group by forming salts when reacting with acid.

There are a number of alcohols are available. But only a few of them are used as drugs of abuse as follows:-

1.Ethanol (Ethyl Alcohol)

2.Methanol (Methyl Alcohol)

3.Diethylene Glycol

Here we deal with ethanol only which is mainly used as a drug of abuse.

Mechanisms

Ethanol is a CNS depressant and works through GABA mediated receptor actions.

Metabolism and Kinetics

Ethanol is metabolized by the liver to acetaldehyde by alcohol dehydrogenase and further to acetic acid by aldehyde dehydrogenase. Acetaldehyde is harmful to the liver and prolonged usage may lead to liver necrosis and fatty liver.75% of the alcohol is metabolized in the liver.

Alcohol is absorbed through the small intestine and stomach into the blood.

The absorption is more if the alcoholic concentration of the drink is between 20 to 25%. As the concentration increases further absorption is lessened by delayed movement from the stomach to the intestine. Absorption is less even if the concentration goes lesser than 20%. Food and other beverages also slow down the absorption.

Alcohol is excreted through kidney and respiration.

The enzyme Microsomal Ethanol Oxidizing System in the liver increases the metabolism of alcohol on chronic use and causes tolerance.

Therapeutics

1.Methanol poisoning by preventing its oxidation by alcohol dehydrogenase in the liver

2.Ethylene glycol poisoning by the same method mentioned above

3. Recent researches have found that one drink of Red Wine may prevent the episodes of CAD. (Coronary Artery Disease)

Ethanol Toxicities

A.Acute:-

1.Euphoria,

2.Disinhibition

3.Slurred speech

4.Reduced vision

5.Ataxia

6.Smooth muscle relaxation

7.Cardiac depression

8.Loss of consciousness 

9.Respiratory depression and death if a blood level exceeds 500 mg/dL.

B.Chronic

1.Deficiency in thiamine associated with Wernicke-Korsakoff syndrome.

2.Liver damage

3.GI irritation and ulcer formation

4.Sexual dysfunction-Gynacomastis (lake of estrogen in the male)

5.High B.P.

6.Dilated Cardiomyopathy.

7.Increased risk of stomach cancer.

Alcohol is contraindicated during pregnancy.

Delirium-Tremor- Chronic Drinker's withdrawal symptoms

1.Tremor

2.Anxiety

3.Tachycardia

4.Delusions

5.Agitations

Abuse suppressants

1.Disulfiram

2.Metronidazole

3.Cephalosporins

4.Procarbazines

The above medicines if taken along with alcoholic drinks they inhibit its liver metabolism and thereby produce unpleasant effects such as nausea, hypotension, and vomiting and thereby discourages the drinking habits.