Letters to the Editor Dear Sirs, Dabigatran is an oral thrombin inhibitor which has been approved for prevention of stroke or embolism in atrial fibrillation (AF) patients as an alternative to vitamin K antagonists (VKAs), based on the results of the RELY trial (1). Dabigatran has been introduced into clinical practice although issues like laboratory monitoring, its use in elderly patients, drug-and food-interactions and an antidote have not been completely clarified (2). Aggressive promotion of the drug has already raised criticism (3). In clinical practice, dabigatran is prescribed to patients with comorbidities that were presumably not present in the RELY trial, as illustrated by the following case. In February 2012, an 85-year-old man was admitted because of gross haematuria and urinary retention. The patient had a history of arterial hypertension for 40 years, AF since 25 years, chronic obstructive pulmonary disease since 12 years, renal failure since 10 years, and a non-disabling lefthemispheric stroke at age 81 years. At age 82 years prostate cancer with osseous metastases was diagnosed, and anti-androgen therapy with leuprorelin started. Because of AF he has been treated with phenprocoumon for eight years. Despite constant international normalised ratio (INR) values between 2.0 and 3.0, the patient suffered from two recurrent non-disabling ischaemic strokes in the territory of the left middle cerebral artery in October 2011. After complete recovery, neurologists switched from