5PSQ-106 Analysis of adverse drug reactions leading to hospital admission in a regional hospital

<h3>Background and Importance</h3> Adverse Drug Reactions (ADR), which are harmful and unintended effects related to medication, can increase morbidity and mortality. According to literature, the incidence of hospital admissions (HA) due to ADR range between 1–28%; leading to hospital stays and related cost between 1–8 days and €2,000–6,000, respectively. Gastrointestinal and nervous systems disorders are the most common adverse effects; being drugs acting on nervous system as mainly involved on them <h3>Aim and Objectives</h3> Primary objective is to determine the prevalence of HA due to ADR. Secondary objectives are to describe: groups of drugs involved, adverse effects, length of hospital stay, and associated costs <h3>Material and Methods</h3> Between January-2022 and August-2023 we conducted a retrospective observational study, evaluating proportion of ADR-HA in relation to emergency department (ED) visits by ADR, and total HA. Furthermore, we describe: drugs involved in ADR according to first level of Anatomical Therapeutic Chemical classification (anatomical system); and adverse effects according to organ and system injured (fifth level of MedDRA hierarchy). Length of hospital stay (LOS; in days) and associated costs (in euros, according to official fees) due to these ADRs were also calculated. Qualitative outcomes were expressed as percentages, and quantitative ones as mean ± standard deviation <h3>Results</h3> During the study period, 272 ED visits for ADR occurred, of which 135 (49.6%) required HA, representing 1,4% of all-cause HA. Mean age for patients with ADR-HA was 69±19 years, and 53.3% were women. The mean LOS for ADR-HA was 6.3±4.6 days, with an average cost of €6,749.6±4,964.7, mainly due to gastrointestinal (n=26; 19.3%) and nervous system disorders (n=17; 12.6%). Drugs mainly involved were those acting on cardiovascular system (n=38; 28%), nervous system (n=36; 27%), and antineoplasic and immunomodulatory agents (n=26; 19%) <h3>Conclusion and Relevance</h3> In line with findings by other authors, our study showed an incidence of ADR-HA of 1,4%, with LOS and associated cost around 6 days and €6,700 per HA, respectively; mainly due to gastrointestinal and nervous system disorders. However, drugs acting on cardiovascular system were most commonly involved in HA-ADR in our study, which focused on hospitalisation; unlike other studies that included ED setting, where drugs acting on nervous system predominated <h3>References and/or Acknowledgements</h3> <h3>Conflict of Interest</h3> No conflict of interest