Fluindione and drug reaction with eosinophilia and systemic symptoms: an unrecognised adverse effect?

Fluindione is an oral vitamin K antagonist (indanedione derivative) exclusively marketed in France and Luxembourg, known to have immuno-allergic adverse effects such as hepatitis, fever or interstitial nephritis. A few cases of drug reaction with eosinophilia and systemic symptoms (DRESS) have been reported with fluindione. The aim of the present study was to investigate fluindione-induced DRESS cases reported in France and to describe their characteristics. We searched for potential cases of DRESS with fluindione reported in the French pharmacovigilance database since 2000. Thirty-six cases of DRESS were included and concerned 17 women and 19 men. The mean age was 65 years (median: 68 years, range: 28-95 years). Kidneys and liver were the most frequent organs involved. Thirty-five cases were serious. In 5 cases, the effect was life-threatening. Most of the patients recovered. Fluindione was the only medicine suspected in 26 cases. Skin patch tests, performed in 10 cases, were positive with fluindione in 9 cases. Fluindione is not known to be a frequent cause of DRESS. However, the number of reports found is probably underestimated. The seriousness of DRESS, as all immuno-allergic adverse effects, contraindicates fluindione reintroduction. Coumarinic derivatives are the alternatives in patients who need oral anticoagulant treatment.