Importance of hypersensitivity in adverse reactions to drugs in the elderly

Background: The use of drugs in the elderly is very extensive because of the frequent occurrence of chronic diseases. Adverse drug reactions (ADRs) commonly occur in geriatric patients receiving multiple therapeutic regimens. In the literature, little attention has been given to ADRs in the elderly, and particularly to allergic reactions. Objective: The aim of the present study is to provide data on possible inappropriate prescriptions in the elderly in relation to allergic reactions and to identify a list of drugs which are likely inducers of allergic reactions. Methods: We retrospectively evaluated ADRs in patients referring to Immunoallergy Unit of Hospital Policlinico in Bari on the basis of Beers criteria. Among adverse reactions, hypersensitivity reactions were extracted and a comparison between different age groups was assessed. Results: Out of 823 patients with ADRs, in 30.6% hypersensitivity drug reactions (HDR) were diagnosed. Data about drug intake, comorbidities and clinical presentation were collected, aiming to identify possible risk factors. An evaluation of drugs most commonly involved was assessed. Conclusions: HDR are reported to represent 5-10% of all ADRs, while in our study population the prevalence was about 30%. This suggests the need to develop strategies to minimize the incidence of drug allergy in the elderly, as well to reduce the phenomenon of inappropriate prescriptions.