Drugs are substances that change chemical reactions in the body.
Mecidal drugs relieve disease and illness and are extrensivley tested before being used
Recreational drugs (e.g. alchahol/tabacco are taen by people because they like the effects they have on their bodies, but they may be very addictive
Developing New Drugs
New medical drugs have to be tested to ensure they work and are safe. Extensively tested for toxicity, efficancy and dose. 3 Main Stages of Testing:
- The drugs are tested using computer models and human cells grown in the lab. Many substances fail this test because they damage the cells or do not seem to work.
- Drugs that pass that test are then tested on animals. A typical test would be giving a known amount of the substance ot the animals then monitoring them carefully for side effects.
- Drugs that have passed the animals tests are used in clinical trials. Tested on healthy volunteers to check they are safe. Very low doses are given at the begining. If no problems, further clinical trials are done to find optimum dose for the drug.
Double blind trials
It is important to be sure that a drug really does have posotive effects rather than people feeling better simply because they are expected to feel better when taking the experiment. This is called the placebo effect.
Double blind trials aim to stop placebo effect. Some patients are given the drug and others are given the placebo. A placebo is designed to appear exactly the same as the drug itself, but does not actually contain the drug.
Doctors and patients are not told who have recieved the drug and who have recieved the placebo until the trial is over.
Thalidomide is a medical drug that caused serious damage to unborn babies in the 1950's and 1960's
Developed as a sleeping pill but was also useful for easing morning sickness in pregnant women. But had not been tested for use in that way.
By 1960 thalidomide was found to damage the development of unborn babies, espcially if it had been taken in the first four to eight weeks.
The drug led to arms or legs of the babies being very short of incompletely formed.
As a result, thalidomide was banned. Drug testing also made more rigorous than before.
Thalidomisde is now used as a treatment for leprosy and bone cancer. Its use is heavily regulated, however, to prevent a repeat of the problems it caused in the last century.
Alcohol and Nicotine
Drugs change chemical processes in the body. People may become dependant on the drug or become addicted to it.
- The alcohol in alcholic drinks (wines, beer, spirit's) is ethanol, which is a depressant
- It slows down signals in the nerves and brain.
- Alcohol is addictive. Long term effects include damage to the liver and brain, and it is often the cause of weight gain.
Nicotine is the addictive substance in tabacco smoke. It reaches the brain within 20 seconds and creates dependancy so that smokers become addicted.
Smoking increases the risks of
- Heart disease and strokes
- Miscarriage, premature birth and low birth weight
- Lung cancer, mouth cancer and throt cnacer
- Prescription drugs that have been dangerously modified.
- Substances banned by the law
- Using them can cause health problems
Heroin and cocaine are very addictive, Like ecstacy, they can damage the heart and circulatory system. Cannabis smoke contains chemicals that cause mental illness in some people
- Buying the drugs can put people in difficult situations (financially)
- Injecting a drug using a needly that someone else has used may lead to diseases from infected blood (HIV, Hepatitis)
- Users of illegal drugs may turn to crime to pay for their habit, this effects lifes of others.
Many more people use legal drugs. This means the overall impact of health from legal drugs is greater than the overall impact of illegal drugs.
Some drugs are capable of artifically improving athletes performance. These include;
- Stimulants- These boost heart rate and other body functions
- Anabolic Steroids- These Stimulate the growth of muscles
Some of these drugs are banned by the law, but others are legally avaliable on prescription or even in some medicines avaliable from the pharmacy.
But all are prohibited from sporting regulations.