The Medicines
How do medicines work?
Most medicines work by either mimicking the structure and action of molecules that naturally occur in your body, or directly attacking pathogens.
Copying naturally occuring molecules
Many medicines work because they mimic chemicals that naturally occur in your body.
In order to understand how they work, we need to gather a wide range of evidence such as:
the chemical structure of the receptor - often by X-ray crystallography
the chemical structure of the active ingredient - often by a combination of analytical methods such as mass spectrometry, UV-Vis spectroscopy, NMR (you will learn about these in year 12 chemistry)
how the active ingredient binds to the receptor - is it a chemical bond (ionic, covalent) or interaction (weak dispersion forces)?
which part of the receptor does the active ingredient bind to?
what is the normal action of the receptor in the cell?
does the medicine switch the normal action of the receptor on or off? For how long?
Fighting pathogens
In order to treat infections from different types of pathogens, we need to understand how they work, and what their weak points are. There are many different ways to combat these diseases. For example, if we can design molecules that break down the cell walls of bacteria, those bacteria will die. But this mechanism won't work for bacteria that don't have cell walls. Conversely, many antiviral medications are aimed at preventing a virus from getting inside a human cell, rather than killing them (note: can something die if it was never alive?). Below we discuss a few examples of the many methods scientists have come up with to combat these diseases.
Some methods are more effective than others, but scientists also have to weigh up the side effects. Is the treatment good enough to justify negative side effects?
Unfortunately, just because a medicine once worked to combat a pathogen, doesn't mean it always will. You may have heard the term resistance in the news.
As pathogens are also living things, they can evolve to reduce their vulnerability to certain medicines. Scientists are concerned that many antibiotics will not be useful for much longer, which means that it is really important for us to keep developing new medicines. But who is going to fund this expensive research, particularly when we have a large range of antibiotics available right now?
The E$$ENTIAL MEDICINE$ project is hoping we might inspire you to become involved in solving this problem with us.