Fludarabine monophosphate (9-beta-D-arabinofuranosyl-2-fluoroadenine-5′-monophosphate) is a synthetic purine analogue, related to both the antileukemic pyrimidine analogue, cytarabine, and to the antiviral agent, vidarabine. Unlike vidarabine, fludarabine is resistant to deamination in vivo by the enzyme adenosine deaminase, making it an active antineoplastic agent. Fludarabine is effective in the treatment of lymphoid malignancies including chronic lymphocytic leukemia and non-Hodgkin’s lymphoma .

The most common adverse effect of fludarabine is myelo-suppression with neutropenia. Less common adverse effects include neurotoxicity, nausea, vomiting, diarrhea, somnolence and transient elevations in hepatic enzymes or creatinine. Pulmonary toxicity has been previously incidentally reported in the literature , in abstract format and as case reports . We report a life-threatening case of recurrent fludarabine-associated pulmonary toxicity requiring mechanical ventilation occurring 24 days after receiving fluda-rabine monotherapy for relapsed non-Hodgkin’s lymphoma.