Adverse drug reactions: mechanisms and assessment.

Adverse drug reactions (ADR) are an important clinical problem. They account for about 5% of all hospital admissions and cause death in approximately 0.01% of surgical patients. The mechanisms leading to ADR beyond IgE-mediated allergy are still poorly understood. The importance of chemically reactive drug metabolites and the involvement of T-lymphocytes in many drug hypersensitivity reactions have been highlighted in recent years. ADR are diagnosed on clinical grounds and the temporal relation between drug intake and the appearance of the symptoms. Allergy tests are required in the further assessment of the reaction. By means of skin tests, in vitro tests and provocation tests information about the culprit drug, the mechanism involved and possible alternatives can be obtained.