Unit 1 Description of a Pharmacy Grammar

How does a medicine or drug act on the body?

There are many different diseases and medical conditions and thousands of medicines and drugs have been produced to help people who need treatment. Each has its own way of working and we each react differently so the process is very complex and difficult to understand. Here are some examples of ways in which medicines and drugs work:

Aspirin

Enzymes are large protein molecules which control the chemical reactions in our bodies. When cells are injured, an enzyme makes substances called prostaglandins which aggravate inflammation, fever and pain. Aspirin works by blocking the action of the enzyme which makes the prostaglandin and at the same time relieving the pain and inflammation in other ways.

Antibiotics

As a part of the body's defence against disease it produces antibodies to invading bacteria, but if these are not able to combat the disease, medicines may have to be taken as well. Penicillin and other antibiotics kill invading bacteria by weakening the bacterial cell wall and causing the bacteria to swell and burst. Human cell membranes have a different chemical structure from the bacteria and are not damaged by these drugs.

Penicillin also helps to reduce the bacterial cell division, and this slowly helps defeat the invading bacteria.

The correct dosage of the antibiotic must be taken and the whole course of treatment followed. This is because problems can arise if antibiotics are not used according to doctor's instructions. The bacteria can become resistant and so the drug gradually becomes less effective.