The cytosine arabinoside (Ara‐C) syndrome

Abstract
Four patients with non-Hodgkin lymphoma and two with acute lymphocytic leukemia (ages 4 years 4 months to 16 years 6 months) exhibited a unique reaction to intravenously administered cytosine arabinoside (Ara-C) given alone as a part of the previously reported LSA2-L2 treatment protocol. The syndrome was characterized by fever, myalgia, bone pain, and occasionally by chest pain, maculopapular rash, and conjunctivitis. Each of the eleven episodes of this syndrome occurred within 6–12 hours of drug infusion and always abated after cessation of Ara-C. Prior to the reaction, patients had been on therapy for an average of 13.5 months during which they were exposed to 2298–5387 mg/m2 (mean of 3200 mg/m2) of Ara-C. The high incidence of this syndrome (50% of our patients on the LSA2-L2 regimen and 33% of those receiving Ara-C) has not been previously reported. Considering the prolonged exposure to Ara-C and our inability to document infections in the patients or pyrogens contaminating the drug lots, the most likely explanation for this syndrome is a hypersensitivity reaction to Ara-C. Prevention of these symptoms with corticosteroids supports this contention and provides a reasonable alternative to discontinuing Ara-C.