[Overdose in Vitamin K antagonists administration in Dakar: epidemiological, clinical and evolutionary aspects]

Vitamin K antagonists (VKA) are widely used for the prevention and curative treatment of thromboembolic events. This study aims to describe the epidemiological, clinical and evolutionary aspects of overdose in Vitamin K antagonists administration and determine its hemorrhagic factors. We conducted a monocentric cross-sectional descriptive study at the Principal Hospital in Dakar. All patients with an INR greater than 5 were included. We studied patients' gender and age, VKA used, drug use period, indications, INR value, associated drugs, presence of hemorrhage, immediate management and evolution. We enrolled 154 patients. Acenocoumarol was the most prescribed VKA. Sex ratio favoured women. The average age was 63 years. Overdose was asymptomatic in 43% of patients. Hemorrhagic symptoms were mainly represented by gingival bleeding, epistaxis. Major bleeding episodes were found in 8.6% of patients and they were represented by melena in 6 patients (3.9%), deep muscle hematoma in 2 patients (1.3%) and intracerebral parenchymal hematoma in 2 patients. Two patients had cardiovascular collapse associated with deglobulisation. Nonsteroidal anti-inflammatory drugs (NSAIDs) assumption was noted in 21% of patients. VKA assumption was suspended transiently in all patients. Mortality was 2%, due to intracranial hemorrhage. The reduction in VKA overdose requires caregivers to manage overdose factors and provide proper patient education.