Incidence of Adverse Drug Reactions at a University Hospital in Southern Brazil

We aimed to evaluate the incidence of adverse drug reactions (ADRs) at a hospital, determine the variation in the incidence of ADRs between genders and among age groups, and determine the pharmacological class most often involved in ADRs. A longitudinal prospective study was conducted over a period of 5 months by using an active search in all hospital units. Four hundred forty-six patients were followed during their hospitalization; 103 showed ADRs, resulting in a 23% overall incidence. Suspected ADRs were identified in 136 patients. From this group of patients, 9 reactions were classified as definite (6.6%), 77 as probable (56.6%), and 50 as possible (36.8%). Female gender, patient age less than 65 years, and hospitalization in the Gynecology and Obstetrics Ward were factors associated with a higher incidence of ADR development. The active search is a suitable instrument for assessing the incidence of ADRs in the hospital.