Frequency and Severity of Adverse Drug Events by Medication Classes: The JADE Study

Objective Adverse drug events (ADEs) are a significant concern in daily practice; however, the profile of high-risk drugs remains unclear. Our objective was to categorize high-risk medication classes according to frequency and severity of ADEs. Methods The JADE study is a prospective cohort study of 3459 hospitalized adult patients. We investigated the ADEs and medications prescribed to the patients. The rate of ADEs for each medication class was calculated by dividing the number of ADEs by the number of patients who received each medication class on admission. Results Overall, 14,435 medications were ordered on admission for patients (median 4; interquartile range, 2-6). Electrolytes and fluids were most frequently prescribed (1876 patients, 54%). Sedatives, antibiotics, peptic ulcer drugs, and analgesics were also commonly prescribed. The frequency was similar in both elderly and younger patients. Among 1010 identified ADEs, antibiotics were most frequently associated with ADEs (31 ADEs per 100 prescribed patients on admission). In patients 65 years and older, corticosteroids, anticonvulsants, laxatives, nonsteroidal anti-inflammatory drugs, and antipsychotics were the 5 most frequent medication classes causing ADEs following antibiotics. In patients younger than 65 years, antibiotics were also the most frequent cause of ADEs, followed by laxatives, lipid-lowering agents, anticonvulsants, and corticosteroids. Among cardiovascular agent-associated ADEs, 46% were fatal or life threatening in elderly patients, whereas antihypertensives were most often associated with fatal or life-threatening ADEs (25%) in younger patients. Conclusions The medication classes frequently associated with ADEs did not necessarily induce severe ADEs.