Harmful Drug Reactions Result in 700,000 ER Visit Each Year

A new federal study published in the Journal of the American Medical Association, revealed that more than 700,000 ER visits each year are caused by the harmful reactions to some of the most frequently used medicines. Allergic reactions and accidental overdoses related to prescription drugs were the most common cause of serious illnesses. The worst offenders were the blood-thinner warfarin, the diabetes drug insulin and the heart medicine digoxin along with Amoxicillin, aspirin and trimethoprimsulfamethoxazole, an antibiotic. The study also revealed that ER visits for those over 65 were twice that of younger people. ABSTRACT National Surveillance of Emergency Department Visits for Outpatient Adverse Drug Events Daniel S. Budnitz, MD, MPH; Daniel A. Pollock, MD; Kelly N. Weidenbach, MPH; Aaron B. Mendelsohn, PhD, MPH; Thomas J. Schroeder, MS; Joseph L. Annest, PhD Context: Adverse drug events are common and often preventable causes of medical injuries. However, timely, nationally representative information on outpatient adverse drug events is limited. Objective: To describe the frequency and characteristics of adverse drug events that lead to emergency department visits in the United States. Design, Setting, and Participants Active surveillance from January 1, 2004, through December 31, 2005, through the National Electronic Injury Surveillance System–Cooperative Adverse Drug Event Surveillance project. Main Outcome Measures: National estimates of the numbers, population rates, and severity (measured by hospitalization) of individuals with adverse drug events treated in emergency departments. Results: Over the 2-year study period, 21 298 adverse drug event cases were reported, producing weighted annual estimates of 701 547 individuals (95% confidence interval [CI], 509 642-893 452) or 2.4 individuals per 1000 population (95% CI, 1.7-3.0) treated in emergency departments. Of these cases, 3487 individuals required hospitalization (annual estimate, 117 318 [16.7%]; 95% CI, 13.1%-20.3%). Adverse drug events accounted for 2.5% (95% CI, 2.0%-3.1%) of estimated emergency department visits for all unintentional injuries and 6.7% (95% CI, 4.7%-8.7%) of those leading to hospitalization and accounted for 0.6% of estimated emergency department visits for all causes. Individuals aged 65 years or older were more likely than younger individuals to sustain adverse drug events (annual estimate, 4.9 vs 2.0 per 1000; rate ratio [RR], 2.4; 95% CI, 1.8-3.0) and more likely to require hospitalization (annual estimate, 1.6 vs 0.23 per 1000; RR, 6.8; 95% CI, 4.3-9.2). Drugs for which regular outpatient monitoring is used to prevent acute toxicity accounted for 41.5% of estimated hospitalizations overall (1381 cases; 95% CI, 30.9%-52.1%) and 54.4% of estimated hospitalizations among individuals aged 65 years or older (829 cases; 95% CI, 45.0%-63.7%). Conclusions: Adverse drug events among outpatients that lead to emergency department visits are an important cause of morbidity in the United States, particularly among individuals aged 65 years or older. Ongoing, population-based surveillance can help monitor these events and target prevention strategies. Author Affiliations: Division of Healthcare Quality Promotion, National Center for Infectious Diseases, Coordinating Center for Infectious Diseases (Drs Budnitz and Pollock and Ms Weidenbach), Office of Statistics and Programming, National Center for Injury Prevention and Control (Dr Annest), Centers for Disease Control and Prevention, Atlanta, Ga; Office of Drug Safety, Center for Drug Evaluation and Research, US Food and Drug Administration, Rockville, Md, and Epidemic Intelligence Service, Office of Workforce and Career Development, Centers for Disease Control and Prevention (Dr Mendelsohn); and US Consumer Product Safety Commission, Bethesda, Md (Mr Schroeder). Dr Mendelsohn is now director of epidemiology, Product Safety, MedImmune, Gaithersburg, Md. JAMA. 2006;296:1858-1866.