(5b) drugs development

• Know that medical drugs are developed and must be tested before being used to relieve illness or disease.

  • Drugs like aspirin and paracetamol are relatively safe and widely used as analgesics (pain-killers).

  • Anti-cancer drugs are a big area of development in the pharmaceutical industry, though they often have side effects, and must be thoroughly tested before licensed for use.

• Be aware that drugs may also be used recreationally as people like the effect on the body.

• Know that some drugs are addictive, and not always those you think of as dangerous.

  • Drugs like heroin and cocaine are highly addictive, caffeine (in tea and coffee) and nicotine (in cigarette smoke and tar) are also addictive!

• Know that some athletes take drugs to improve performance.

  • eg stimulants or steroids to build up muscle tissue.

• Appreciate that people cannot make sensible decisions about drugs unless they know their full effects.

• Given data-information, you are expected to use your acquired skills, knowledge and understanding to:

  • evaluate the effect of statins in cardiovascular disease,

  • evaluate different types of drugs and why some people use illegal drugs for recreation,

  • evaluate claims made about the effect of prescribed and non-prescribed drugs on health,

  • consider the possible progression from recreational drugs to hard drugs,

  • evaluate the use of drugs to enhance performance in sport and to consider the ethical implications of their use.

• Appreciate that scientists are continually developing new drugs.

• Know that when new medical drugs are devised, they have to be extensively tested and trialled before being used.

  • Know that new drugs are constantly being developed and must be tested in a series of stages to find out if they are safe and effective.

  • Know that new drugs are extensively tested for toxicity (serious side-effects), efficacy (capacity for producing the desired medical effect) and dose (effect of different amounts):

    • know drugs are tested in the laboratory, using cells, tissues first and then live animals, but drugs that affect the whole body eg a blood pressure reducing drug, a blood cancer drug etc., can only be satisfactorily tested in the end by using 'real people'.

    • A drug may tested on two or more live animals, to many people's objection (animal rights ethical issue) but many scientists would argue this reduces the risks when testing the drug with human volunteers.

    • know that clinical trials involve healthy volunteers and patients.

    • Very low doses of the drug are given at the start of the clinical trial to look for side-effects.

    • The first drug trials would be on healthy people, before doing further drug trials testing the drug on ill patients.

    • If the drug is found to be safe, further clinical trials are carried out to find the optimum dose for the drug - the dose that is most effective with little side-effects.

    • It should be noted that it is almost impossible to develop a drug that has no side-effects with anyone. I'm afraid we all have a slightly different body chemistry and a certain % of people will show some undesired reaction to the drug.

    • In some double blind trials, some patients are given a placebo, which does not contain the drug.

    • A placebo, which is delivered like the actual drug (eg look and taste), contains no medication and enables the clinicians to distinguish the effects of the drug from the volunteers who have not received the drug.

    • Its a sort of 'fair test' or 'blank check' idea should be familiar with in your school laboratory under the heading 'How Science Works'.

    • You can even do an extra check to avoid 'human bias' by doing a 'double-blind' drug trial in which the doctors or pharmaceutical scientist don't know who is or is not given the drug until all the results are collated. This hopefully avoids any prejudice on the part those conducting the trial.

    • Neither the doctors nor the patients know who has received a placebo and who has received the drug until the trial is complete.

  • You should understand that tissues and animals are used as models to predict how the drugs may behave in humans.

• Know that thalidomide is a drug that was developed as a sleeping pill in the 1950s.

  • It was also found to be effective in relieving morning sickness in pregnant women.

  • Thalidomide had not been tested for use in pregnant women, in particular it was not tested for relieving morning sickness.

    • Also, it was not known that the drug could pass through the placenta and into the foetus, where unfortunately, it caused abnormal limb development.

    • Thousands of babies were affected and about half survived with missing limbs or malformed limbs.

  • Unfortunately, after many babies born to mothers who took the drug were born with severe limb abnormalities the drug was then banned.

  • As a result, drug testing has become much more rigorous in an attempt to reduce the incidence of serious side-effects from newly developed drugs..

  • More recently, thalidomide has been used successfully in the treatment of leprosy and other diseases.

Keywords, phrases and learning objectives for this part on drugs to combat disease

Be able to describe the importance of developing new drugs to combat non-communicable diseases.

Be able to describe, how and why testing new drugs is important (clinical drug trials) to estimate the effectiveness of a new drug and explain the need for, and use of, a placebo in clinical trials