A Case series of Acute Methotrexate Toxicity.

ABSTRACT Acute methotrexate toxicity represents a serious medical emergency with significant morbidity and mortality. This case series aims to characterize clinical presentations, risk factors, and outcomes of patients with acute methotrexate toxicity admitted to a tertiary care hospital. We retrospectively analyzed six patients who presented with acute methotrexate toxicity. Clinical presentations, laboratory parameters, management strategies, and outcomes were evaluated. All patients received leucovorin rescue therapy and supportive care. The cohort comprised six patients (median age 63 years, range 54-96 years) with 67% female predominance. All patients presented with mucocutaneous manifestations, predominantly oral ulcers (100%). Pancytopenia was observed in all cases with available complete blood counts. Dosing errors were the primary etiology in 67% of cases, with patients erroneously taking weekly doses daily. Additional risk factors included advanced age and chronic kidney disease. Laboratory findings revealed severe neutropenia (median total leukocyte count range 480-5300 cells/mm3), with progressive hematological deterioration requiring intensive monitoring. Treatment consisted of immediate methotrexate discontinuation, leucovorin rescue therapy (15 mg IV), granulocyte colony-stimulating factor in severe cases, and supportive care. Five patients (83%) recovered completely within 5-14 days, while one elderly patient with chronic kidney disease died from complications, yielding a 17% mortality rate. Acute methotrexate toxicity results primarily from dosing errors. Mucocutaneous ulcers serve as early warning signs of systemic toxicity. Early recognition, prompt leucovorin rescue therapy, and aggressive supportive care are crucial for favorable outcomes. Enhanced patient education and monitoring protocols are essential for prevention.