Adverse drug reactions and adverse drug events in elderly patients consulting a hospital emergency unit

Objective: To determine adverse drug events (ADE) and adverse drug reactions (ADR) in elderly patients consulting a third level hospital emergency unit (EU). Design: Cross sectional study. Patients and methods: Four hundred patients aged sixty years or older consulting the EU (Caldas Hospital, Manizales, Colombia) (March-May 2004). Data on demographic characteristics, primary diagnosis, associated conditions and evaluation of medications intake were taken from the clinical records. Functional state was measured according with Barthel’s index. Type and severity of ADE and ADR were categorized. Algorithms were used for ADR operational assessment. Results: The mean of age of patients was 72.8±8.2 years, and 52.3% were females. Frequency of ADE and ADR was 6.8%. Organic systems affected were 48.1% gastrointestinal, 37% endocrine and metabolic. 28.3% of the patients were not on medication. Mean use of medications per patient was 2.9±1.7. Type of medications involved, in order of frequency, was antiplatelet, hypoglicemic, diuretic, NSAIDs and cardiovascular. Intake of medication (Odds Ratio (OR)=3.52, (IC95% =1.58-7.87), and functional status (OR=3.54 (IC95% = 1.6-7.82) were associated factors for emergency unit admission for ADE or ADR. In the logistic regression the presence of an associated illness constituted the only independent associated factor for hospitalization (OR=3.2 IC 95% 1.95-5.42). Conclusions: ADE and ADR are frequent, important and not well studied causes for consultation of elderly patients at the EU. The number of associated illness was the main risk factor for hospitalization by ADE or ADR.