Article Type

Original Study


Objectives The aim of this work was to study the complications of 6-mercaptopurine (6-MP) drug therapy developed during the course of chemotherapy in children with acute lymphoblastic leukemia (ALL). Background Mercaptopurine is an anticancer drug used in the routine treatment of pediatric patients with ALL, which is administered daily during maintenance phases of chemotherapy. The principal and potentially serious toxic effects of 6-MP are bone marrow toxicity and hepatotoxicity. Patients and methods Twenty-five children with ALL were included in the present study. Initially, complete blood count, liver function tests (alanine aminotransferase, aspartate aminotransferase), bone marrow examination, immunophenotyping, and cytochemical analysis were performed. Markers for hepatitis B and C using PCR were applied/determined. Data on toxicity were traced during the maintenance phase. Results During the maintenance phase, 16.0% of patients were seen to have febrile neutropenia grade 2 (ANC < 1.5 to >1.0 × 109/l), 56.0% to have febrile neutropenia grade 3 (ANC < 1.0 to >0.5 × 109/l), and 28.0% to have febrile neutropenia grade 4 (ANC < 0.5 × 109/l). Sixteen percent of patients had mildly elevated levels of liver enzymes up to 200 IU/l, 32.0% had elevated levels of liver enzymes more than 200 IU/l, and 52.0% of patients had normal levels of liver enzymes. Eight percent of patients did not need drug interruption, 24.0% needed interruption for up to 1 week, and 68.0% of patients had to discontinue 6-MP for more than 1 week. An overall 16.0% of patients required 6-MP dose modification by 25-50% reduction of total dose, 4.0% needed 6-MP dose modification by less than 50% reduction of total dose, and 80.0% did not need dose modification throughout the maintenance course. The total number of mortality cases was 10 (40.0%) of 25 patients. Conclusion 6-MP could induce hematological toxicity and several forms of hepatotoxicity. 6-MP dose reductions should be performed throughout the maintenance phase according to the protocol.