Severe methotrexate toxicity precipitated by intravenous radiographic contrast

Methotrexate (MTX), a widely used anticancer agent, and intravenous iodinated contrast used for radiographic studies can both cause acute renal failure. Their combined exposure may place patients at higher risk for renal failure. This report describes 2 pediatric patients with MTX toxicity precipitated by the use of intravenous radiographic contrast. One patient recovered with leucovorin rescue therapy, whereas the second patient responded to carboxypeptidase-G2. Both patients suffered MTX-related toxicities including myelosuppression and mucositis, but recovered full renal function and tolerated further high-dose MTX therapy. These cases suggest that intravenous iodinated contrast should be avoided in patients receiving high-dose MTX.