8. Pharmacology
Nick Southorn
• It’s all about class!95
• What do I need to know about these drugs?97
• In the clinic98
• Conclusion98
How do I get my head around all of this?
Good question! You will already have an understanding of the normal physiologic workings of the human body and the pathologic processes of common conditions – inflammation, for example (and if it’s all a bit vague, pharmacology is a good topic to remind you what physiology is all about). Understanding the drugs is literally working out how they reduce the symptoms of that pathology – they do it by either disease modification or symptom management. For this reason it is strongly advised that “pharmacology” is studied within study relating to disease. As a physio you will not be expected to be a font of all knowledge regarding medicine – that is why we have doctors! With that in mind, allow yourself to be satisfied with a general knowledge of the drugs rather than the complexities.
It is usually a good idea in any case to develop your own “glossary of words/terms” for pharmacology to help you get to grips with it all. This may sound time consuming but just have a look at how simple the definitions can be in order to have a decent effect. Any glossary should only have a “reminder” rather than a full description.
• Opioid
– Any substance that binds to an endogenous (within the body) opioid receptor antagonistically. They are both neurotransmitters and neurohormones producing both inhibition (expressed as analgesia in the spinal cord) and excitation (expressed as nausea in the chemoreceptor trigger zone). They may be endogenous (produced within the body) or exogenous (administered for the purpose of analgesia).
• Receptor agonist
– A drug that binds to a receptor and stimulates it.
• Receptor antagonist
Learn about the advantages and disadvantages of administration such as:
• oral (pills, liquid, etc.)
• intravenous (IV)
• transdermal (patches)
• rectal (suppositories)
• inhaled
• subcutaneous
• buccal (under the top lip)
• epidural, subarachnoid.
There are two ways really of studying about medicine: learning about the class of drug, i.e. how the types of drug work and the names of the drugs that fall into that class; and learning about the specific drug and to what class it belongs. Either way, you will find it gets easier as you go along as more and more drugs belong to the same class.
It is difficult to explain the difference between the two. Learning about the class will ensure that the prominent detail of your learning is the science of the drug whereas learning the names and action will ensure you know what that drug does but perhaps fail to recall the later learned details of how it works. It is for that reason that I can say that if you have an interest in pharmacology and medical physiology, or if your course requires it, you will find learning about the biochemistry of medicine fascinating and worth while. However, if medication is not your interest (and perhaps that is the reason you became a physiotherapist and not a doctor) then learn the names and the basic action – that will suit you much better. The net result is essentially the same – you see you patient is taking simvastatin and you can confidently predict that he has high cholesterol!