ABSTRACT
The rate of adverse drug reactions (ADRs) in patients taking drugs is higher than many doctors suspect. It is estimated that ADRs occur in 10-20" of all patients prescribed drugs and are the cause of up to 10" of all general practitioner (GP) consultations, 4" of all hospital admissions and 6-10" of admissions to geriatric wards, and about one in 1000 deaths. Adverse drug reactions can be classified into four broad types, namely: Type A, Type B, Type C and Type D. The Committee on Safety of Medicines (CSM) asks for reports of all serious adverse reactions or suspected adverse reactions to any drug, and for special reporting of all suspected adverse reactions to newly-introduced drugs. Some patients are particularly at risk from adverse reactions and merit special caution in prescribing. Drug interactions are also important and must be considered, especially where high-risk patients are on high-risk drugs. Drug interactions may be pharmacokinetic or pharmacodynamic.
