Review of an article in "Chemistry Review" by Brendan Colgan/Y11/2000.

One out of twenty people suffer from asthma.  Medication for asthma is used in the form of an inhaler. The symptoms of asthma are wheezing and breathlessness.  1800 people die from asthma every year in Britain alone.  Modern-day drugs allow asthma sufferers to lead relatively normal lives.  Paul Scholes , a  Manchestser United and England footballer suffers from asthma and uses two inhalers to cope with the disease. 

    At the minute there is no cure for asthma as the mechanisms in the body that trigger it are far from understood.  Bronchodilators can be used to relieve narrowed and enflamed airways to the lungs.  Bronchodilators release chemicals, which attach to parts of cells in our bodies to get a response.  The response from bronchodilators  are  the relaxation of the smooth muscle tissue resulting in  the widening of the airways.  In 1969 Glaxo released a product called Ventolin , which is an inhaler which delivers a bronchodilator.  Ventolin contains an organic compound  , salbutamol , which is extremely effective for the symptoms of asthma.  31 years on it is still in use.

 Drug discovery and salbutamol   

Biochemists had  to identify the chemical compound in nature that was responsible for keeping airways open , and to determine it’s chemical structure. They  assessed many chemicals which had the right effects but had many unwanted side affects  e.g. adrenalin , side affects – a faster heart beat and an increase in blood pressure. They needed a chemical similar to adrenalin but with minimal side affects.  The scientists studied adrenalins molecular structure and tried to change certain parts of it to reduce side affects.  Many methods could be used to do this e.g. changing the size of the substituents or to change the electronic size of groups.  Adding or removing hydrogen bonding groups is another method.  By changing the nitrogen substituent blood pressure side affects were removed.  After other adjustments to the chemical adrenaline triol was formed. This chemical had few side affects , had asthma relieving properties and lasted approximately 4 hours.  One side affect adrenaline triol did have was increased heart rate so one final adjustment was made.  Again the nitrogen substituent was changed in size.  The new compound salbutamol was made.  A longer lasting compound , salmeterol was produced  which lasted for up to 12 hours.  Salbutamol is still the drug of choice for acute attacks. 

This article shows the importance of chemistry in the development and discovery of new and extremely important drug compounds.

     Chemistry Department: Loreto College, Coleraine.