ジャーナル・オブ・ファーマコビジランス

概要

Thrombocytopenia Possibly Induced By Dabigatran: A Case Report

Arianna Deidda, Maurizio Rapallo, Maria Dolores Sofia, Leandra Meloni, Simona Francesca Lampus, Claudia Pisanu, Giovanna Cadeddu, Donatella Garau, Maria Del Zompo and Maria Erminia Stochino

Dabigatran, a reversible direct thrombin inhibitor, is a new oral anticoagulant developed for long-term prevention of thromboembolic disorders whose safety profile is not completely known yet. Here we report a case of dabigatraninduced severe thrombocytopenia which was signaled to our Regional Center of Pharmacovigilance.

An 84 year old Caucasian man started dabigatran due to a permanent atrial fibrillation. Five months later he was admitted to the emergency department following a skin eruption. Physical examination revealed a hemorrhagic necrotic skin lesion in the lumbosacral region. Blood tests showed a severe thrombocytopenia, with a platelet count of 16.000 mm3. The patient was hospitalized and dabigatran was promptly suspected to be the causative agent of thrombocytopenia, so the drug was discontinued and one week later platelet count completely normalized. Segmental distribution of the cutaneous lesions suggested hemorrhagic herpes zoster, so the patient was treated with oral valacyclovir and local gentamicin, with complete remission after a few months.

To the best of our knowledge, severe thrombocytopenia induced by dabigatran has never been previously reported in literature, although the Italian National Pharmacovigilance database of the Italian Medicines Agency reports seven cases of thrombocytopenia associated with dabigatran, including ours. According to Naranjo algorithm severe thrombocytopenia was possibly due to dabigatran, which suggests a careful monitoring of patients being treated with this drug.