Eleven-Year Trend of Drug and Chemical Substance Overdose at a Local Emergency Hospital in Japan

The purpose of this study was to investigate long-term trends of overdose in the emergency department of a regional core hospital in Sendai, Miyagi Prefecture, Japan, and to identify patient characteristics as well as drugs and chemicals associated with overdose. Patients who visited the emergency department from January 1, 2010, to December 31, 2020, and were diagnosed with a drug or chemical overdose were included in the study. We conducted a descriptive analysis based on the data collected. In total, 577 patients (mean 38.4 years old, female 75.0%) were considered, and 16.8% had a history of repeated overdose. The number of patients during the study period showed a downward trend, with slight increases in 2012 and 2020. In addition, the top four drugs suspected of causing overdose were over the counter (OTC) antipyretic analgesics and cold medicines (N=97), followed by flunitrazepam (N=80), etizolam (N=72), and brotizolam (N=70). There was a decreasing trend in overdose, and OTC medicines, sedatives, and anxiolytics were the primary medications causing overdose. OTC antipyretic analgesics and cold medicines were the most common suspected overdose drugs, with an increasing trend in the later years.