Drugs and how they work

A drug is any substance that is taken into the body that alters or influences chemical reactions in the body.

What are drugs

Medical drugs

These drugs are designed to suppress pain , counteract the symptoms of flue or kill pathogenic bacteria

Aspirin Paracetamol Morphine Antibiotics

Types of drugs

Hallucinogens

These drugs cause psychedelic visions for the drug user.

Lysergic Acid Diethylamide or LCD

Types of drugs

Stimulants

These are mood-enhancing drugs which give the user a short-lived feeling of wellbeing and energy.

Examples

Cocaine , ecstasy and amphetamines.

Types of drugs

Depressants (downers)

Slow down the brain and central nervous system.

Examples are alcohol, beer, wine, vodka, gin etc heroin, tranquilizers, sleeping pills

Types of drugs

Drugs such as nicotine and heroin , interfere with the way that the nervous system works.

Mood-enhancing drugs, such as heroin and nicotine act at synapses in the nervous system and change the way in which neurons send impulses.

Drugs are broken down in the body by enzymes and the products are excreted.

Drugs in the body

Many drugs have the potential to be addictive. If the body comes to rely on the drug a person can become addicted and feel the need to take it regularly.

The body’s metabolism may become used to the drug. The liver may produce more enzymes to break it down so that the dose of the drug has to increase to have the same effect the user first experienced.

Drug addiction

in the case of heroin, synapses may produce more target molecules and if these do not combine with heroine this leads to an increase in the feeling of pain.

The person has become dependent on the drug and cannot survive without it.

When the people stop taking the drug they may experience withdrawal symptoms which can vary from nausea to severe cramp.

Drug tolerance

Antibiotics are a group of chemicals made by microorganisms (bacteria and fungi) that are used in chemotherapy as they kill pathogens or stop their growth.

Antibiotics destroy pathogens by disrupting cell wall formation, inhibiting protein synthesis and metabolism in the pathogen cell.

Antibiotics

Antibiotics cannot kill viruses since they have no cell wall and live inside host cell, taking over their metabolic processes.

Antibiotics

Biology of heroin Heroine is a compound modified from morphine. Heroine is a powerful depressant that slows down the

nervous system. Heroine resembles the natural body’s painkillers,

known as a natural opiate. First time users experience euphoria- feeling of

contentment and intense happiness.

HEROIN

Heroin becomes part of the body’s metabolism and the body quickly gets used to the drug.

More painkillers are needed to prevent them sending impulses to the brain. But the body does not produce more of its own natural painkillers.

Addiction to heroin

Heroin addicts may turn to crime to obtain money for their next dose.

Shared needles have resulted in the spread hepatitis and HIV amongst addicts who inject heroin.

A user who stops taking the drug experiences very un pleasant withdrawal symptoms. These can include sleeplessness and hallucinations, muscle cramps, sweating, vomiting and nausea.

Social problems

Biology of alcohol Alcohol is absorbed into the blood very quickly since

it is small molecule that does not need to be digested It is absorbed by liver cells and broken down by

enzymes so that its concentration in the blood decreases gradually.

Alcohol is a depressant. It affects the brain by slowing down the transition of nerve impulses.

Alcohol

Crime , family disputes, marital breakdown, child neglect and abuse, absenteeism from work, vandalism, violent crime including murder.

Alcohol and other drugs are involved in many road accidents.

Social problems of alcohol

Stomach ulcers, heart disease and brain damage. If heavy drinking continues then the liver becomes

full of nodules. This is the condition known as cirrhosis.

Long-term effects of alcohol

Biology of tobacco smoke

Nicotine

It is absorbed very quickly through the alveoli to enter

the bloodstream. Nicotine makes the heart beat faster

and narrows the arterioles. - Tar

Is a black sticky material that collects in the lungs as a smoke cools. Tar irritates the lining of the airways and stimulates them to produce more mucus.

Smoking and healthcomponents of tobacco smoke

Carbon monoxide

This is a poisonous gas. It is absorbed by hemoglobin in red blood cell.

It reduces the volume of oxygen that blood can carry.

Components of tobacco smoke

Chronic bronchitis and emphysema The bronchi become blocked as there is less space

for air to flow. Large amounts of mixture of mucus, bacteria and white blood cells are produced, which people attempt to cough up.

The break down of alveoli becouse of partcles bacteria and tar , reducing gas exchange is called emphysema.

Diseases caused by smoking

Lung cancer Heart desease

Diseases caused by smoking

Questions ??