Introdução: Reação Adversa a Medicamento (RAM) é qualquer resposta prejudicial ou indesejável e não intencional que ocorre com medicamentos em doses normalmente utilizadas no homem para profilaxia, diagnóstico, tratamento de doença ou para modificação de funções fisiológicas. Atualmente, representa uma das principais causas de morbidade e mortalidade na área da saúde. Objetivo: Analisar as reações adversas a medicamentos e fatores associados em pacientes ortopédicos tratados com antibióticos. Método: Coorte prospectiva conduzida com 273 pacientes ortopédicos internados no Instituto Nacional de Traumatologia e Ortopedia, Rio de Janeiro, Brasil. A coleta de dados ocorreu nos anos de 2012 e 2013, por meio de instrumento composto por variáveis demográficas-clínicas e terapia medicamentosa. Para identificação das RAMs realizou-se o monitoramento ativo, composto de: entrevista, análise de prontuários e exames laboratoriais. As RAMs consideradas graves foram analisadas por meio do formulário do Instituto Catalão de Farmacologia, Espanha. Na análise dos dados utilizaram-se os testes Mann-Whitney, Qui-Quadrado, exato de Fisher e regressão logística, com significância de p 0,05. Resultados: A incidência de RAM foi de 41%. O grupo com RAM apresentou maior média de idade (43,3; DP 10,9), tempo de internação (72,7; DP 40,9) e número de medicamentos concomitantes (13,2; DP 4,1). Os fatores associados foram número de medicamentos, uso de antimicobacteriano (OR 2,44; IC 1,3944,270) e carbapenêmicos (OR 2,38; IC 1,167 4,872). Identificaram-se 466 RAM, cuja maioria (67,1%) foi classificada como leve. No grupo de pacientes com RAMs graves identificaram-se leucopenia (46,6%), insuficiência renal aguda (40%) e hepatite medicamentosa (26,6%). Os antibióticos foram os principais medicamentos suspeitos de causar as RAMs graves (76,4%), sendo os mais frequentes (23,5%) formados pela tríade: amicacina + vancomicina + piperacilina com tazobactam. Conclusão: A incidência de RAM é maior quando se incorpora ao serviço de farmacovigilância a técnica de monitoramento contínuo dos pacientes hospitalizados e se utiliza a analise de exames laboratoriais como preditores para suspeitas de RAMs potencialmente graves

Introduction: Adverse Drug Reaction (ADR) is any noxious, undesired or unintended response which occurs in the use of normal dosages of drugs for prophylaxis, diagnosis, treatments or for modifying physiologic functions. Nowadays, ADR represents one of the main causes of morbidity and mortality in the health service area. Objective: To analyze the occurrence of adverse reaction to drugs and factors related to orthopedic patients treated with antibiotics. Method: The prospective cohort study was conducted in 273 orthopedic patients hospitalized at the Brazilian Institute of Traumatology and Orthopedics in Rio de Janeiro. The data collection was made during the years 2012 and 2013, using instruments composed by demographic-clinical variables and drug therapies. With the purpose of identifying occurrences of ADRs, during active monitoring, interviews were conducted, medical charts and exams were analyzed. In addition, the occurrence of ADRs considered harmful was analyzed by using a form provided by the Catalan Institute of Pharmacology, Spain. In the study of the data collected, was made use of Mann-Whitney tests, Chi-Squared test, Fishers exact test and logist regression, with p-value 0,05. Results: The occurrence of ADRs was of 41%. This group was composed by individuals with major age rage (43,3, SD 10,9), major time spent hospitalized (72,7; SD 40,9), and quantity of concurrent drugs used (13,2; SD 4,1). Also, the related factors were the number of drugs, the usage of Antimicobacterial agents (OR 2,44, CI 1,394-4,270) and Carbapenemases (OR 2,38; CI 1,167 4,872). During the study, there were identified 466 ADRs, and the majority (67,1%) was classified as low-grade. Additionally, in the group of patients with harm adverse reactions, it was possible to identify leukopenia (46,6%), acute kidney failure (40%) and drug-induced hepatitis (26,6%). The antibiotics were the main drugs suspected to be the cause of potentially harmful ADRs (76,4%), being the most frequent (23,5%) formed by the triad: amikacin + vancomycin + piperacillin-tazobactam. Conclusion: The occurrence of ADRs is higher when the practice of continuous monitoring of hospitalized patients is incorporated to the pharmacovigilance service, and the analyzes of lab exams are used as predictors for the suspicion of potentially harmful ADRs