Idiosyncratic drug-induced neutropenia and agranulocytosis

Background/Introduction: Few data is currently available on neutropenia and agranulocytosis related to drug intake. Aim: We report here data on 203 patients with established idiosyncratic drug-induced agranulocytosis, followed up in a referral centre within a university hospital. Design: Data from 203 patients with idiosyncratic drug-induced agranulocytosis were retrospectively reviewed. Methods: All cases were extracted from a cohort study on agranulocytosis in the Strasbourg University Hospital (Strasbourg, France). Results: The mean age was 61.6 years old (range: 18-95), the gender ratio (F/M) was 1.3. Several comorbidities were present in 63.5%. The most frequent causative drugs were: antibiotics (49.3%), especially beta-lactams and cotrimoxazole; antithyroid drugs (16.7%); neuroleptic and anti-epileptic agents (11.8%); antiviral agents (7.9%); and platelet aggregation inhibitors as ticlopidine and acid acetylsalicylic (6.9%). The main primary clinical manifestations during hospitalization included: isolated fever (26.3%); septicaemia (13.9%); documented pneumonia (13.4%); sore throat and acute tonsillitis (9.3%); and septic shock (6.7%). The mean neutrophil count at nadir was 0.148 x 109/L (range: 0-0.48). All febrile patients were treated with broad-spectrum antibiotics and 107 (52.7%) with hematopoietic growth factors. The mean duration of haematological recovery (neutrophil count >= 1.5 x 109/L) was 7.8 (range: 2-20). This mean duration was reduced to 2.1 days (range: 2-16) (p = 0.057) with hematopoietic growth factors. Outcome was favourable in 91.6% of patients; seventeen died. Thirty-seven patients (18.2%) required intensive care. Discussion/Conclusion: The present study demonstrated that idiosyncratic drug-induced agranulocytosis is a relative rare events; that antibiotics, antithyroid, neuroleptic and anti-epileptic agents, and platelet aggregation inhibitors are the main incriminated drug classes; that agranulocytosis typically serious, with at least 50% exhibiting severe sepsis and a mortality rate < 10%; and that modern management of such disorder may reduce the infection-related mortality.