This unit of study is intended to provide knowledge in a number of fundamental areas that guide and provide evidence to support the safe, effective and appropriate use of medicines. These fundamental areas of knowledge start with an understanding of the relationship between drugs interacting with target sites in the body and the effect produced (i.e. pharmacodynamic principles) and understanding the physiological and physicochemical factors that influence the movement of drugs around the body and the time course of exposure of body tissues and blood to drugs (i.e. pharmacokinetics). These principles involve developing concepts and mathematical relationships to explain drug activity in patients and to guide appropriate drug dosage regimen selection. To support this, relevant mathematical and statistical principles involving calculus are introduced during this unit of study. This unit will also explore reasons behind variability in response to medicines among different individuals. The effects of disease, other drugs, demographics and the genetic basis for variable response will be introduced. Basic pharmacogenetic principles for explaining and predicting pharmacodynamic and pharmacokinetic variability in response are an important part of this unit of study. Students are also exposed to the notion that medicines may produce adverse effects (as well as beneficial ones). The mechanisms underlying adverse reactions to drugs and how these are classified are explored as are the principles for detecting and avoiding these unwanted effects. Ultimately, many options often exist to manage illness. While the fundamental principles described above assist in understanding how individual drugs should be used, they do not alone provide knowledge to select among alternative options. This unit will introduce students to methods that are used to provide evidence of efficacy and safety of different therapeutic options and to define the place in therapy of these options. To do this, the principles that underpin evidence based medicine (including the clinical trial and pharmacoepidemiology) and the notion of levels of evidence are introduced. Exposure to these principles is intended to develop in students a basic understanding of how to critically evaluate therapeutic options. The evaluation of therapeutic options requires an understanding of statistical methods, which are also introduced during this unit of study.