Pharmacoeconomics of adverse drug reactions.

Abstract Adverse drug reactions (ADRs) are common causes of hospitalization and lead to large costs to society. The cost of hospitalization is, however, only a part of the total costs as most adverse reactions never come to clinical attention. There are two main costs associated with ADRs, cost of treating illnesses due to ADRs and cost of avoiding them. The main objective of this study was to discuss the social costs of ADRs from an economic point of view. We also reviewed the literature and summarized studies investigating cost and occurrence of adverse reactions. Three different approaches to assess the costs of ADR are distinguished. The first is cost studies, where the following three steps must be done to estimate the costs: define ADR, estimated the incidence of ADRs and measure the costs of ADRs. Most cost studies have focused on hospitalizations due to ADRs and the literature shows that about 3-7% of all hospitalizations are caused by ADRs. The second approach concerns costs and benefits of safety: the decision to prescribe, use, distribute or produce a drug involves both costs and benefits, and decisions makers must weigh costs of ADRs against costs of avoiding them. The third approach discusses regulations and mechanisms for achieving an optimal balance between costs and benefits of drug therapies. The problem with ADRs is, from an economic point of view, not a problem of minimization but of optimization, to find the right balance between costs and benefits.