Adverse reactions to medicines continue to present a burden on healthcare, causing considerablemorbidity and mortality. As well as knowing about the benefits of medicines, healthcare professionalsneed to understand the problem of adverse drug reactions and be aware of how they can be preventedand managed. This book provides the current state of knowledge of basic mechanisms of adverse drugreactions (ADRs). The main focus is on drug reactions because they are the most difficult to deal with.There is also a description of several examples of ADRs that serve to illustrate specific aspects of ADRmechanisms. Eventually the book shows that ultimately better methods are needed to predict whichdrug candidates are likely to cause ADRs and which patients are at increased risk. But at present researchseems to be far from this goal.