ABSTRACT
Antimetabolite drugs are rarely associated with grade 3 or 4 mucositis. However specific side effects such as bone marrow suppression, pancytopenia, hospitalization, high cost limit the use of intravenous methotrexate. Here we report a case of 25-year-old girl patient with Acute Lymphoblastic Leukemia (ALL) treated with 24 hour methotrexate in her continuous phase of chemotherapy. After 12 hours of completing the treatment she developed oral mucosal pain & she was not able to speak. After a week, her White Blood Cell (WBC) count was 600/cumm with fever and she could not speak and eat or drink. So she was hospitalized for few days till she can drink something. We report high grade mucositis with methotrexate. Hematologists should be aware of this possible side effect to undertake early intervention.