GCSE AQA Biology 1 Drugs

GCSE AQA Biology 1 Drugs

1. Drug: A substance which alters the way the body works

   • Chemical changes caused by drug can lead to addiction
     • If drug isn't taken - withdrawal symptoms
   • Examples of addictive drugs
     • * Heroin * Cocaine * Nicotine * Caffeine

2. Types of drugs

   • Medicinal
     • e.g. antibiotics
     • Prescription or non-prescription
     • Can be dangerous if misused
   • Performance-enhancing
     • Can improve performance in sport
     • Different types
       • Anabolic steroids
         • Increase muscle size
       • Stimulants
         • Increase heart rate
     • Can have negative health effects
       • Steroids can cause high blood pressure
     • Some banned by law, some prescription-only - ALL are banned by sporting bodies
     • Ethical problems
       • For taking drugs
         • * Athletes have right to make own decision about whether taking drugs is worth risk or not * Drug-free sport isn't really fair anyway - have access to different facilities, equipment, coaches...
       • Against taking drugs
         • * Unfair that people gain advantage * Athletes may not be fully aware of serious health risks
   • Recreational
     • Can be illegal or legal
       • Illegal drugs divided into: * Soft - can still be harmful * Hard - thought as more addictive and more harmful
     • Reasons for use
       • * Pleasure/enjoyment * Relaxation * Stress relief

3. Cannabis and hard drug use

   • Almost all users of hard drugs have tried cannabis first but most users of cannabis don't go on to use hard drugs
   • The link is because...
     • It's a stepping stone
       • Effects cause desire to try harder drugs
     • It's a gateway drug
       • Brings people into contact with drug dealers
     • It's because of genetics
       • Certain people are more likely to take take drugs generally - they will try other drugs too...

4. Legal drugs

   • Some have more of an impact than illegal drugs
     • Smoking
       • * Causes heart and lung disease * Tobacco smoke causes cancer * Nicotine is addictive
     • Alcohol
       • * Affects nervous system - slows down body's reactions * Too much can lead to impaired judgement, poor coordination and unconsciousness * Excessive drinking can cause liver disease and brain damage * It's addictive
       • Cost of crime and loss of money to economy
     • More people take them
     • NHS spend lots of money treating people
     • Cause grief to people affected

5. Drug claims

   • Statins
     • * Prescribed drugs used to lower risk of heart & circulatory diseases * Lower blood cholesterol and reduce risk of heart disease in diabetics * Large-scale research has been done to compare people who had and hadn't taken statins
   • Cannabis
     • * Illegal drug * Scientist have investigated whether it causes mental health problems - results vary

6. Testing medicinal drugs

   • 1) Drugs are tested on human cells and tissues
     • * Can't use human cells and tissues for drugs that affect whole or multiple body systems
     • 2) Drugs are tested on live animals
       • * To see whether drug works, to find out its toxicity and the best dosage * Law states any new drug must be tested on 2 different live mammals
       • 3) Drugs are tested on human volunteers
         • * Drug is tested on healthy volunteers to find out side effects (v. low dose is given) * If results are good, drug is tested on people with the illness to find optimum dose (most effective/few side effects) * Double-blind trials are used - patients are put into 2 groups (one is given drug and one is given placebo) * When finding out effect of drug - allows for placebo effect * Doctors and patients don't know - doctors monitoring and analysing be influenced

7. Thalidomide

   • Was intended as a sleeping pill
     • Was tested for that use
     • Was found to be effective in relieving morning sickness
       • Wasn't tested for that use - didn't know affected fetus causing abnormal limb development
         • * Some babies born with no arms or legs * 10000 babies affected - only half survived
         • Drug was banned - more rigorous testing introduced
           • Recently thalidomide has been used for treating leprosy