Epilobium parviflorum, hemorrhagic risk with anticoagulants

Plants have a crucial importance in our ecosystem. They contain complex mixtures of compounds that can interact with various therapeutics. Among them, the small-flowered willowherb (Epilobium parviflorum) has seen its use expand in recent years, particularly for prostate diseases. The aim of this work is to demonstrate the risk of interaction between the use of E. parviflorum and medications, especially anticoagulants, illustrated by the case of our patient suffering from dilated cardiomyopathy, treated with acenocoumarol 4 mg, a vitamin K antagonist (VKA), for over a year. The recent intake of small-flowered willow herb tea, rich in tannins and flavonoids, increased the patient's INR (International Normalized Ratio), indicating an increased risk of haemorrhage. A therapeutic education session was then held, with management of interactions and monitoring of the patient until stabilisation. The intake of E. parviflorum or any other plant with anticoagulants requires rigorous pharmacological therapeutic monitoring to anticipate the risk of bleeding and improve the quality of life of patients.