This chapter includes general aspects regarding the definitions and
mechanisms of occurrences of adverse drug reactions (ADRs). They can be realized
through non-immunological (type A reaction) or immunological (type B reaction)
pathways and can be dose-dependent or independent. A new type of ADR is
encountered in oncology departments in patients taking monoclonal antibodies. It is
known as drug-induced apoptosis and is presented in this chapter. The mechanisms and
classification of the severity of these reactions, as well as the particularities of acute,
chronic and chronic-delayed ADRs, are also explored. The severity can be patient- or
drug-related. In the chapters that follow, specific system- and organ-related ADRs are
presented.
Keywords: Acute, Adverse drug reaction, Allergy, Apoptosis, Ahronic,
Hypersensitivity, Iatrogenic, Idiosyncrasy, Monoclonal antibodies, Recurrent
