Acute Methotrexate Toxicity Managed with Leucovorin and Pegylated Granulocyte Colony-stimulating Factor: A Report of Two Cases and Review of Literature

Acute methotrexate (MTX) toxicity is most commonly due to overdose of the drug, which may be due to the patient's noncompliance to doctor's orders or physician's prescription error. Other causes include acute renal failure, concomitant use of other drugs, and genetic susceptibility. MTX toxicity presents with pancytopenia, mucositis, hepatotoxicity, pulmonary toxicity, and acute renal failure. Treatment involves a polypragmatic approach which includes vigorous hydration, urinary alkalinization, administration of leucovorin, and glucarpidase. Administration of granulocyte colony-stimulating factor should be considered in cases of severe neutropenia. Here, we present two cases of acute MTX toxicity in chronic plaque psoriasis presenting with ulceration of psoriatic lesions and mucosal ulceration successfully treated with leucovorin and pegylated granulocyte colony-stimulating factor (G-CSF). This case report demonstrates that G-CSF might be lifesaving by contributing to rapid reconstitution of leukopoiesis.