Importance of Adverse Drug Reactions

IMPORTANCE OF ADVERSE DRUG REACTIONS

Adverse drug reactions are a major clinical problem (Bates et al., 1995a,b, 1997; Classen et al., 1997; Einarson, 1993). A meta-analysis suggested that ADRs were between the fourth and sixth commonest cause of death in the United States in 1994 (Lazarou, Pomeranz and Corey, 1998). A large prospective study in the United Kingdom has shown that ADRs were responsible for 6.5% of all hospital admissions (Pirmohamed et al., 2004). Adverse drug events are associated with an increased length of stay in hospi-tal of 2 days and an increased cost of approximately $2500 per patient (Bates et al., 1997; Classen et al., 1997). ADRs can also have many other indirect effects (Table 8.1), which in total, highlight the overall impor-tance of ADRs in modern medicine.