BackgroundAntimicrobials are widely used in hospitals and are often associated with adverse drug reactions (ADRs). The objective of this study was to determine the incidence of ADRs caused by antimicrobials and classify them according to the type of reaction, the class of antimicrobials used, causality, severity and avoidability.MethodsA prospective cohort study was carried out with paediatric patients for 6 months. Causality was verified using the Naranjo and Liverpool algorithms, the severity was verified with the adapted scale of Hartwig and the avoidability was verified with the Liverpool Avoidability Assessment Tool.ResultsA total of 303 patients were followed, and 18.2% (55/303) of them had one or more ADRs during the hospital stay. Just over half of the patients (28/55) had diarrhea. The most used antimicrobials were beta-lactams and second-generation cephalosporins. Suspicions were classified mainly as possible 78.6% (55/70) according to the Naranjo algorithm, and as probable 48.6% (34/70) according to the Liverpool algorithm. The antimicrobial most involved with ADRs was cefepime. The risk of manifesting ADR was greater with the use of some antimicrobials such as clindamycin (relative risk (RR) 3.0, CI 1.67 to 5.4), as well as with the increase in hospitalisation days (OR 1.022, CI 1.008 to 1.036) and in the number of antimicrobials prescribed (OR 1.649, CI 1.360 to 2.001).ConclusionADRs were observed in approximately one-fifth of patients and were mostly gastrointestinal, moderate, unavoidable and with variable causality, depending on the algorithm used.

Introduction Adverse drug reactions (ADRs) to antiinfectives affect especially hospitalized children and contribute to increased morbidity, mortality, length of stay, and costs in healthcare systems. Objective To assess ADRs associated with antiinfectives use in Brazilian hospitalized children. Methods A prospective cohort study was conducted in five public hospitals over six months. Children aged 0 to 11 years and 11 months who were hospitalized for more than 48 hours and prescribed antiinfectives for over 24 hours were included. Results A total of 1.020 patients met the inclusion criteria. Of these, 152 patients experienced 183 suspected ADRs. Most reactions were related to the gastrointestinal system (65.6%), followed by skin reactions (18.6%). Most reactions were classified as probable causality (58.5%), moderate severity (61.1%), and unavoidable (56.2%). Our findings showed that ADRs were associated with increased length of stay (p < 0.001), increased length of therapy (p <0.015), increased days of therapy (p = 0.038), and increased number of antiinfectives prescribed per patient (p < 0.001). Conclusion Almost 15% of hospitalized children exposed to antiinfectives presented suspected ADRs. Their occurrence was classified as probable, of moderate severity, and unavoidable. ADRs were significantly influenced by the length of hospital stay and the number of antiinfectives prescribed per patient.