Management of medication errors in oncological patients: a cross-sectional study and case reports of pharmaceutical interventions in a university hospital in central-west Brazil

Abstract

Introduction Antineoplastic chemotherapy (ACT) is widely used, but involves significant risks due to protocol complexity and inherent toxicity. Pharmacists play a key role in validating ACT prescriptions to enhance patient safety. Objective To analyze medication errors during ACT prescribing and describe pharmaceutical interventions performed to manage these errors at a Federal University Hospital in the Central-West region of Brazil. Methodology This cross-sectional study, supplemented with case reports, was conducted between January 2023 and July 2024. A total of 382 prescriptions for 208 oncology outpatients were analyzed; only prescriptions with previously identified medication errors were included in this study. Medication errors were classified as decision-making or writing errors according to the Pharmaceutical Care Network Europe (PCNE) classification and Dean et al. (2000), and categorized by severity using the NCC MERP framework. Data were extracted from an institutional database and validated by an oncology specialist pharmacist. Only deviations with potential pharmacological or clinical impact were classified as decision-making errors, excluding minor operational adjustments. Results Decision-making errors occurred in 91.6% (n = 358/391) of prescriptions, primarily due to inappropriate diluent volumes (91%), while writing errors were observed in 8.4% (n = 36/391), mainly from missing clinical information. Pharmaceutical interventions were accepted in 99% of cases, preventing errors from reaching patients. Most errors were intercepted before administration (NCC MERP Category B), though two cases had potential clinical consequences (Category C) and one required patient monitoring due to communication issues (Category D). Conclusion Specialized oncology pharmacists play a critical role in ensuring the safety of ACT prescribing. The high proportion of decision-making errors observed within this selected sample emphasizes the need for systemic improvements, such as integrated electronic prescribing and continuous pharmacist-led oversight, to reduce preventable errors and enhance patient safety.