Adverse drug reactions reported over 5 years in a regional university hospital

Adverse drug reactions (ADRs) are closely associated with increased morbidity and mortality rates, prolonged hospitalization durations, and higher healthcare costs. This study aimed to estimate the incidence, clinical features, and reporting status of ADRs to improve the current ADR reporting system and prevent recurrent ADRs in hospitals. This retrospective study was conducted at a regional referral hospital. Patients diagnosed with ADRs over a 5-year period (2009-2014) were recruited for this study. An ADR was identified as an ADRrelated diagnosis in a patient’s medical record or an ADR registered through the inhospital ADR reporting system. The incidence, culprit drug, clinical manifestations, reporting source, severity, related management, and recurrence rate were assessed. Among 1,112 patients, 1,375 ADR events were collected, an estimated 0.06% of the total number of patient visits. Diagnostic contrast agents (46.4%) were the most common culprit drugs, followed by antibiotics (22.0%), nonsteroidal anti-inflammatory drugs (9.9%), and opioids (4.5%). Skin reactions (67.5%) such as rashes and hives were the most frequent manifestations. Additional ADR-related medical attention was necessary in two thirds of cases. One hundred eighty ADR events (13.1%) were categorized as severe, and 19 patients (1.4%) experienced re-exposure to the culprit drugs. Four patients (0.3%) experienced fatal ADRs. Physicians were the most frequent ADR reporters in the in-hospital ADR reporting system. In conclusion, many ADR events may be overlooked, and re-exposure to causative drugs commonly occurs. Continuous education and maintenance of a reporting system may be important for preventing recurrent ADRs.