Patterns of infection in 41 patients with idiosyncratic drug-induced agranulocytosis

We examined the patterns of infection in 41 consecutive patients with idiosyncratic drug-induced agranulocytosis observed during the past 15 years. All patients were nursed in reverse isolation and treated prophylactically with oral antimicrobials and antifungal compounds. Nine of 41 patients remained without fever and did not need any parenteral antibiotic treatment for full recovery. The other 32 patients developed fever during the period of agranulocytosis and were treated with empirical antimicrobial therapy. Febrile episodes were documented microbiologically in 16 patients (eight with and eight without bacteremia) and clinically in six patients. In the other ten cases the fever was of unexplained origin. The observed pattern of infection was in accordance with the type of infection as reported in cancer patients during the granulocytopenic phase induced by cytotoxic drugs. Ten of 32 febrile patients showed improvement after empirical antimicrobial therapy, whereas three patients died, two of them of a lower respiratory tract infection and one of a massive hemorrhage due to necrosis of the carotid artery. In ten patients the signs and symptoms of infection resolved only after adjustment of the initial empirical scheme. In nine patients the fever persisted even after additional empirical antifungal therapy but subsided after recovery of the granulocytopenia.