Dr Sheila Doggrell
There are a huge number of drugs available in Australia. Thus, there are 27,000 drugs on the Australian Register of Therapeutic Goods (ARTG) and, of these, 3,500 are registered as prescription only.
Firstly, we need to know what pharmacology is: Pharmacology is the study of all aspects relating to drugs or medicines. Some of us, use the term ‘drugs’ to cover medicines (prescription and non-prescription)and drugs of abuse (legal and illicit), and this is how I am going to use ‘drugs’ in this Introduction. The popular press often uses the term ‘drugs’ to mean drugs of abuse, and this can be confusing. Somemedicines can also be drugs of abuse, this further complicates the issue. For example, morphine is both a potent pain reliever and a drug of abuse.
Pharmacology can be divided into two parts; pharmacodynamics and pharmacokinetics. Pharmacodynamics is ‘What the drug does to the body’. Pharmacokinetics is ‘What the body does to the drug’.After administration, the drugs usually has to be absorbed into the body, may be distributed around the body, and/or metabolised, and will eventually be excreted/eliminated. Absorption (A), distribution (D),metabolism (M) and excretion/elimination (E) are sometimes referred to as ADME. These processes are pharmacokinetics, and they may be altered in disease states. This is important, as we most commonlyuse drugs in disease states.