[Idiosyncratic drug-induced agranulocytosis]

Idiosyncratic drug-induced agranulocytosis is a potential adverse event of most drugs, rare but life-threatening. Its annual incidence does not exceed 10 cases per million population in Europe and has remained stable over the past two decades. Its pathogenesis is poorly understood. The principal drugs associated with it are antithyroid drugs, antibiotics including trimethoprim, sulfamethoxazole, and beta-lactamines, ticlopidine, sulfasalazine and dipyrone. Clinical presentation is highly variable but a severe infection is observed in more than one third of cases. Poor prognostic factors include a neutrophil count under 100/mm(3), age65 years, septicemia or shock, and severe comorbidity. Improvement in the management of infectious complications and the use of hematopoietic growth factors in severe cases helps explain that mortality rate has fallen to less than 5%.