Types of Medicines and Their Mode of Action and Use

Chemical medicines comprise man-made molecules created in the laboratory by combining small atoms in a specific sequence and structure. Commonly used atoms include carbon, oxygen, hydrogen and nitrogen, and are usually obtained from petrochemicals derived from crude oil and natural gas liquids. In contrast to some other medicines, chemical medicines are not produced by living cells such as bacteria. In fact, chemical medicines are usually quite simple in design and are produced using chemical processes in large quantities in specialist manufacturing facilities (Figure 1). Many have been used by patients for many decades.