B1.3 Use and Abuse of Drugs

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  • Created by: Fiona S
  • Created on: 17-02-15 19:08

Drugs and Statins

  • Statins are used to treat Heart Disease
  • Statins reduce high cholesterol levels
  • Statins stop the process of Atheroma
  • Liver Damage and Aggression (4 out of 5 patients) are possible side effects

A drug is: a chemical that has an effect on the functioning of the body

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Drug Development and Testing

A Placebo is... when you do a drug test and you give the patient a fake drug e.g. sugar and make them think it is the real drug

Double-Blind Trial - when the patients and the doctors don't know who has the real drug

Random Testing - a black-box testing approach in which software is tested by choosing a random subset of all possible input values. It helps avoid the problem of testing what you know will work.

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Drug Development and Testing

Stage 1: What disease to treat? Researchers target a problematic drug

Stage 2: Preclinical Testing - where scientists and researchers determine what germs, viruses, or bacteria cause the specific disease

Stage 3: First tests in laboratory. The drugs are tested using computer models and human cells grown in the laboratory. Many substances fail this test because they damage cells or do not seem to work

Stage 4: Animal Testing

Phase I - Testing on Students

Phase II - Testing on Patients

Phase III - Final testing and licensing

During Phase I only a few people are used to evaluate its safety, determine a safe dosage and amount and find out if there are side effects.

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Thalidomide

  • Released 1958, and quickly became the best selling sleeping pill and was advertised as safe for pregnant women, even though there was no data to support this
  • Thalidomide was prescribed to pregnant women to treat morning sickness
  • The German drug company who created Thalidomide expected to make a lot of money as alternative sedatives are toxic
  • By 1960, a rare birth defect was appearing. Babies were born without arms or legs. Their hands and feet were attached directly to their bodies. This condition is called phocomelia
  • By 1962, 12000 Thalidomide babies had been born but only 8000 survived. It was estimated a further 12000 had died before birth. It was withdrawn from the UK market the same year
  • Doctors found the chemicals that cause defects in embryos are called teratogens
  • Further research suggested that the drug most affected the embryo if taken between the 20th and 36th day after conception
  • The drug causes defects because it interferes with growth and development of new blood vessels
  • Thalidomide is now used to treat multiple sclerosis, AIDS and the painful inflammation caused by leporasy
  • It also reduces the size of some cancers
  • Thalidomide is being manufactured in the UK, but women are not allowed to enter the factory
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Recreational Drugs

Certain drugs may harm the body. Drugs change the chemical processes in people's bodies so that they may become dependent or addicted to them and suffer withdrawal symptoms without them.

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Cannabis

  • Cannabis is derived from a plant called Cannabis sativa
  • It can be rolled with tobacco in a spliff or joint, smoked on its own in a special pipe, or eaten
  • Cannabis affects short term memory and ability to concentrate
  • Use affects co-ordination, increasing the risk of accidents
  • It can make users paranoid and anxious, depending on their mood and situation
  • Smoking cannabis over a long period of time may increase the risk of respiratory orders, including lung cancer
  • Many users find cannabis hard to quit
  • THC, a chemical that affects the brain, moves into the receptors
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Cocaine

  • Cocaine is a white powder that can be inhaled. Some users inject it.
  • Cocaine is a powerful stimulant
  • The effects last roughly 30 minutes
  • Users are often left craving more
  • Cocaine can cause heart problems and chest pain
  • Heavy use of cocaine can cause convulsions
  • Inhaling cocaine may permanently damage the inside of the nose
  • Users may find their habit expensive and hard to control
  • Users have died from overdose
  • Deep in the brain, cocaine interferes with chemical neurotransmitters and receptors, blocks reabsorption of 'happy' chemicals
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Heroin

  • Heroin is a painkilling drug made from morphine which is derived from the opium poppy
  • It comes as a white powder when pure. It is inhaled, smoked or injected
  • Excessive amounts can result in overdose, coma and in some cases death
  • Heroin is very addictive. Getting the next fix can dominate a user's life
  • Injecting can damage veins and lead to gangrene
  • Sharing needles or syringes puts users at risk of dangerous infections like hepatitis and HIV
  • Withdrawing from heroin can be very hard
  • Binds to a neuroreceptor triggering a reaction in cells 
  • U-Opioid - receptors in brain and spine
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Is smoking Cannabis bad for your health?

Yes

  • Cannabis has a higher concentration of cancer-cause substances (carcinogens) than tobacco
  • It has a higher tar content than tobacco can lead to bronchitis, emphysema and lung cancer
  • It can increase the risk of fainting since it disrupts the control of blood pressure
  • It can lead to mental illness
  • It contains more than 400 chemicals. The main one that affects the brain is known as THC
  • People with heart and circulation disorders or mental illness can be adversely affected by it
  • It may be psychologically addictive

No

  • Its effects are beneficial to patients suffering from various medical conditions including HIV, multiple sclerosis and cancer 
  • Unlike harder drugs, a government report has suggested that a high use of cannabis isn't associated with major health or sociological problems
  • Cannabis is less addictive than amphetamines, tobacco or alcohol, and does less harm to the body
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Can smoking cannabis lead users to harder drugs?

Yes

  • Cannabis may be a 'gateway' drug to more addictive and harmful substances such as heroin and cocaine

No

  • Many cannabis smokers never use any harder drugs
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Legal Recreational Drugs

Tobacco

  • If you are a non-smoker, cilia in your trachea are constantly beating and moving mucus away from the lungs. The mucus traps dirt, dust and bacteria from the air you breathe in the cilia to ensure you remove it all
  • If you are a smoker, the cilia are paralysed by the cigarette smoke. This allows dirt, dust and bacteria to enter the lungs. This makes you more likely to suffer from lungs infections. The mucus also builds up, causing the smokers cough
  • Tar is a poison that can cause lung cancer and is associated with other cancers
  • The build up of tar in the lungs can damage the delicate alveoli, they lose their elasticity and can break
  • Instead of having millions of tiny air sacs, a smoker may end up with far fewer
  • It is difficult to obtain oxygen and this condition is known as emphysema
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Smoking and Pregnancy

  • Carbon Monoxide is a poisonous gas found in cigarettes
  • It is picked up the red blood cells
  • Reduces the amount of oxygen carried in the blood
  • After smoking, 10% of a smokers blood will be carrying carbon monoxide rather than oxygen
  • Especially damaging for pregnant women
  • The amount of oxygen in a pregnant female smokers will be lower than normal and this means her foetus will be deprived of oxygen
  • It may not grow as well as it should and is likely to have low birth mass
  • Such babies are, on average, 200g less than babies whose mothers do not smoke
  • Pregnant women who smoke are also more likely to have miscarriages or a stillbirth
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Alcohol

  • Alcohol is a very commonly used drug
  • In small amounts, it makes people feel relaxed and happy
  • It makes people feel less inhibited, so shy people feel more confident after an alcohol drink
  • However, alcohol has a powerful effect on the body
  • It is very addictive and very poisonous
  • Alcohol is one of the most widely used drug in the UK
  • People have been drinking alcohol for thousands of years
  • The Ancient Egyptians made beer
  • If alcohol was discovered today, it would almost certainly be an illegal drug
  • Alcohol affects the nervous system. It causes: in small amounts it slows down your reactions, larger amounts cause loss of self control, when a lot is drunk, it can lead to unconsciousness, coma and even death
  • Alcohol damages the brain and liver. Brain cells shrink.
  • A person who drinks alcohol for many years may have permanent brain damage
  • The liver becomes damaged because it has the job of breaking down the alcohol into harmless substances. Too much alcohol though can kill the liver's own cells
  • Each year, 30,000 people in Britain are admitted to hospital with liver disease caused by drinking alcohol
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How Alcohol Affects Us

  • After alcohol has been drunk, it passes through the stomach and small intestine and is absorbed into the bloodstream
  • From there it travels to the rest of the body, including the brain
  • It is processed out of the body by the liver
  • Alcohol is a 'depressant'. This means it slows down the reactions in your brain 
  • It lowers some of your inhibitions, making you feel reckless
  • Alcohol affects your physical co-ordination, reaction times and judgement
  • It takes the liver one hour to process one unit of alcohol
  • No matter how fast we drink, the liver can only work at this pace
  • The effects of alcohol can be felt between 10 and 20 minutes after drinking, and sooner on an empty stomach

The effects vary depending on:

  • How much you drink and how quickly
  • What you drink (fizzy or stronger drinks such as spirits are absorbed more quickly)
  • How used you are to drinking
  • Your size and weight
  • Your gender (Women are more affected than men as women tend to be smaller, have more relative body fat and less water in their body. So the concentration of alcohol is higher)
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Steroids and Sports

  • Some athletes take illegal substances to enhance their performance, this is known as 'doping'
  • There are 5 types of doping classes (banned drugs), the common being stimulants and hormonesMany of these drugs are banned by sport governing bodies
  • Although they are performance-enhancing, they have serious health risks
  • Some athletes, footballers and sports people from other fields hope the drugs will give them an edge over all the other people they competing against
  • It is very risky as it is cheating and they don't want to get caught. Drugs can also be bad for a sportspersons health
  • Often they are experimental drugs and the long-term effects of taking them are not yet known
  • Peptide hormones, analogue and anabolic agents all increase the size of muscles or help growth
  • Stimulants speed up parts of the body and the brain to improve reactions and stop you getting tired
  • Narcotic analgesics also stop the effects of tiredness by reducing pain
  • Beta blockers calm you down and slow your heart down
  • Diuretics allow you to lose weight by increasing the amount of urine you pass. They are sometimes used to try and get evidence of a drug out of someone's system
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