IFOSFAMIDE-INDUCED FANCONI SYNDROME

OBJECTIVE: To report a case of possible ifosfamide-induced Fanconi syndrome in an adult with cancer. CASE SUMMARY: A 20-year-old man was treated for an osteosarcoma with a chemotherapy regimen that included ifosfamide, methotrexate, and doxorubicin. Three months after completing therapy he developed polyuria, polydypsia, and bilateral ankle pain. Laboratory findings showed decreased serum concentrations of phosphorus, uric acid, calcium, potassium, and bicarbonate; elevated blood urea nitrogen and creatinine; and increased urinary excretion of phosphorus, potassium, calcium, citrate, and protein. The patient was diagnosed with Fanconi syndrome and osteomalacia. Treatment with oral supplements of potassium sodium, citric acid, calcium and calcitriol collected the electrolyte abnormalities. DISCUSSION: The adverse effect most frequently associated with ifosfamide is hemorrhagic cystitis. The incidence of hemorrhagic cystitis is decreased with the concomitant administration of the uroprotective agent mesna. The development of Fanconi syndrome after ifosfamide therapy has been described previously, although it occurs more frequently in children than adults. The mechanism by which ifosfamide causes renal tubular damage is not well understood, but it appears to involve metabolites of the drug. CONCLUSIONS: The development of renal tubular defects and renal failure should be considered in patients receiving ifosfamide. Although this complication appears more frequently in children, adults also can be affected. Renal function should be monitored closely to detect the appearance of this adverse effect. Renal tubular dysfunction can, as this case illustrates, develop months after completing chemotherapy.