RESUMEN
Abstract In pediatrics, drug therapy is commonly performed through adaptations of the dosage forms to adult use, increasing the risk of adverse drug reactions. In this context, studies assessing the severity and avoidability of the adverse reactions in children, especially those caused by antimicrobials, are still scarce. This work aimed to investigate suspected antimicrobial adverse reactions (ATM-ADRs) in pediatric patients admitted to a public hospital in northeastern Brazil, focusing on causality and avoidability analysis. A cohort study was carried out over a period of six months in a 64-bed pediatric unit. The incidence of suspected adverse reactions caused by antimicrobials was 14.65%. Most reactions were rated as probable (89.13%), with moderate severity (84.78%) and possibly avoidable (45.65%). The analysis indicated that the use of a larger number of medications (p<0.0001) and longer hospital stay (p=0.004) were related to the occurrence of ATM-ADR. Our findings demonstrated that almost half of the suspected reactions could be prevented and that the antimicrobial's clinical management is relevant in this context. Besides, increasingly accurate adverse reaction classification instruments are essential. These results can support the development of therapeutic guidelines addressed to a safe and effective pharmacotherapy in the pediatric area