Drugs and their effects

Drugs are substances that change chemical reactions in the body. Medical drugs relieve disease and illness, and are extensively tested before being used. Recreational drugs such as alcohol and tobacco are taken by people because they like the effects they have on their bodies, but they may be addictive. Cannabis and heroin are illegal recreational drugs that are very addictive.

New medical drugs have to be tested to ensure that they work, and are safe, before they can be prescribed. There are three main stages of testing:

1.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.

2.Drugs that pass the first stage are tested on animals. In the UK, new medicines have to undergo these tests, but it is illegal to test cosmetics and tobacco products on animals. A typical test involves giving a known amount of the substance to the animals, then monitoring them carefully for any side-effects.

3.Drugs that have passed animal tests are used in clinical trials. They are tested on healthy volunteers to check they are safe. Very low doses of the drug are given to begin with. If there are no problems, further clinical trials are done to find the optimum dose for the drug.

If the drug is harmless to everything and cures an illness, it becomes a legal drug.

Thalidomide is a medical drug that caused unexpected and serious damage to unborn babies in the 1950s and 1960s. Thalidomide was developed as a sleeping pill, but women found that it was also good at easing morning sickness when pregnant. Unfortunately, it had not been tested for use in this way. By 1960 thalidomide was found to damage the development of unborn babies, especially if it had been taken in the first four to eight weeks of pregnancy. The drug led to the arms or legs of the babies being very short or incompletely formed. More than 10,000 babies were affected around the world. As a result of this disaster, thalidomide was banned. Drug testing was also made more rigorous than before. Thalidomide 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.

Drugs change chemical processes in the body. Over time, people can find them self addicted or depending on the drug they take, causing them to sometimes suffer withdrawal symptoms if they stop taking the drug. Both alcohol and nicotine are found in tobacco and are legal recreational drugs. However, misuse of them results in health problems.

Alcoholics drink alcohol such as wines, beer and spirits which is ethanol, a kind of depressant, meaning it slows down signals in the nerves and brain. While small amounts of alcohol help people relax, large amounts cause people to lack self-control. Drinkers of alcohol don't tend to realize how much they're drinking, and fall ill as a result. They may become unconscious or even fall into a coma. Alcohol is addictive. Long-term effects of alcohol are damage to the liver and brain, as well as causing weight gain. Pregnant women are warned not to drink alcohol or at least limit how much they drink.

About 114,000 people die every year as a result of smoking-related illnesses. All cigarettes now are sold with health warnings. Nicotine is the addictive substance inside tobacco. It reaches the brain in 20 seconds and creates a dependency so smokers become addicted. 

Smoking increases the risk of:

1. Heart disease and strokes.

2. Miscarriage, premature birth and low birth weight.

3. Lung, mouth and throat cancer. 

illegal drugs include prescription drugs that have been dangerously modified and substances that are banned by law. Ecstasy, cannabis and heroin are illegal, recreational drugs. They can cause health problems.

Health problems

Heroin and cocaine are very addictive. Like ecstasy, they can damage heart and circulatory system. Cannabis smoke contains chemicals that cause mental illnesses in some people. 

Athletes are often under pressure to perform well. Some drugs are capable of artificially improving their performance; these include:

1. Stimulants - these boost heart rate and other body functions

2. Anabolic steroids - this stimulate the growth of muscles

Some of these drugs are banned by law. Others are legally available on prescription or even available from the pharmacy. However, the use of performance-enhancing drugs is very unfair, and can also damage athletes bodies. 

Athlete's can't use performance-enhancing drugs and are often tested to make sure they are not using them.