Biology- Medicine and drugs

Developing new medicines

• New drugs have to be throughly tested before they are sold as medicines
• Drugs are tested to see if they work, to find out if they are toxic and to see if they cause side effects
• Thalidomida was developed as a sleeping drug but not tested for preventing morning sickness, so some babies had birth defects
• The first tests are in scientific laboratories on cells and tissues or organs. If the drug seems to work it is then tested on animals, helthy human volunteers and finally on patients
• Healthy people are given very low doses of the drug to find out if it is safe
• In some trials, with patients, placebos are useed. Placebos do not contain a drug. Half the patient have the drug, the other half the placebo. This is to check kthat the drug being tested really does not have an effect on the patient
• In a double-blind trial, neither the doctor nor patient knows who is given a drug
• Thalidomide was banned and the rules for drug testing were improved
• More recently, thalidomide has been used to treat other conditions, including leprosy, but it is never given to pregnant women

How effective are medicines?

• Statins are drugs which lower blood cholesterol levels. Their use has lowered cardiovascular disease in the population by over 40%
• Double-blind trials should be used to checkif both non-prescribed and prescribed drugs actually work
• Some people prefer to take drugs which are not prescribed by doctors. Herbs are pften used instead of prescribed medicines
• A herb called St John's Wort is sometimes taken to treat depression instead of anti-depressants such as Prozac
• The only way to be sure that the herb works as well as or better than Prozac is to conduct a double-blind trial

Drugs

• Drugs are chemicals which alter the body's chemistry. You can become addicted to some drugs
• Both illegal drugs and legal ones, such as alcohol and tobacco, may harm your body
• Chemicals in cannabis may cause metal health problems
• Heroin and cocaine are very addictive
• Useful drugs,made from natural substances, have been used by indigenous people for a very long time
• Recreational drugs are used by people for pleasure
• If you try to stop taking addictive drugs you will suffer withdrawl symptoms

Legal and Illegal drugs

• Many recreational drugs cause changes in the brain and nervous system. Some are very harmful
• Recreational drugs may be legal or illegal
• More people use legal drugs, so their impact on health is greater then that of illegal drugs
• Medicinal drugs are developed over many years and are used to control disease or help people that are suffereing. Many medicinal drugs are only available on prescription from a doctor
• Nicotine and caffeine (in coffee and coke) are legal drugs which are used recreationally. Alchol is also legal for people over the age of 18 in this country
• There are many health problems associated with legal recreational drugss, e.g. alcoholic poisoning, addiction to nicotine leading to lung cancer from cigarette smoke
• Some drugs used for medicinal purposes can be used illegally, e.g. stimulants used by sports people

Does cannabis kead to hard drugs?

• Cannabis is an illegal drug which must be bought from drug dealers. This can put the user in contact with hard drugs
• The chemicals in cannabis smoke may cause mental illness in some people, particularly teenagers
• Teenagers who smoke cannabis increase their risk of getting depression
• Not all cannabis users go on to use hard drugs
• Nearly all heroin users previously smoked cannabis

Drugs in sport

• Some athletes use drugs to make them perform better 
• Steroids are one type of performance -enhancing drug
• The use of performance-enhancing drug is considered unethical by most people
• Sterios are drugsd which are used to build up muscle mass. Other drugs may be useed to increase stamina
• Strong pain killers are banned because the athlete might ignore an injury and suffer further damage