RESUMO
INTRODUCTION: In university hospital settings most prescriptions are written by junior doctors, who are more likely to make prescribing errors than experienced doctors. Prescribing errors can cause serious harm to patients and drug harm differs among low, middle and high-income countries. In Brazil, few studies have investigated the causes of these errors. Our aim was to explore medication prescribing errors in a teaching hospital, their causes, and underlying factors from the perspective of junior doctors. METHOD: Qualitative, descriptive and exploratory study that used a semi-structured individual interview with questions related to the planning and execution of prescriptions. It was conducted with 34 junior doctors who graduated from twelve different universities located in six Brazilian states. The data were analyzed according to the Reason's Accident Causation model. RESULTS: Among the 105 errors reported, medication omission stood out. Most errors resulted from unsafe acts during execution, followed by mistakes and violations. Many errors reached the patients; unsafe acts of rule violations and slips accounted for the majority. Work overload and time pressure were the most frequently reported causes. Difficulties faced by the National Health System and organizational problems were identified as latent conditions. CONCLUSION: The results reaffirm international findings about the severity of prescribing errors and the multifactorial aspect of their causes. Unlike other studies, we found a large number of violations, which, from the interviewees' perspectives, are related to socioeconomic and cultural patterns. The violations were not seen or mentioned by the interviewees as violations, but as difficulties in accomplishing their tasks on time. Knowing these patterns and perspectives is important for implementing strategies to improve the safety of both patients and professionals involved in the medication process. It is suggested that the exploitation culture of junior doctors' work be discouraged and that their training be improved and prioritized.