RESUMEN
BACKGROUND: Medication reconciliation is advocated to ensure the continuity, safety, and effective use of medicines across transitions of care. CASE REPORT: In this report, we describe the case of a 90-year-old female with previous diagnoses of atrial fibrillation and cutaneous metastatic breast cancer presenting with bilateral ulcerative lesions on the chest wall. The patient was diagnosed with Deep Vein Thrombosis at the Emergency Department and started on rivaroxaban, although the patient was already taking edoxaban. This therapeutic duplication was noticed only one week later, even though she was already experiencing significant bleeding managed through a prescribing cascade. Despite the technical error (action-based), it is possible to identify several weaknesses in the organisation's structure, which provided a trajectory of accident opportunity. CONCLUSION: Anticoagulants are ranked first for the highest priority to receive a medication reconciliation. To achieve an optimal level of medication reconciliation, we ought to recognise and correct latent failures.