Abstract
We report a rare case of hyperammonemic encephalopathy after modified FOLFOX6 therapy (mFOLFOX6). A 72-year-old man was diagnosed with ascending colon cancer, sigmoid colon cancer, multiple liver metastasis, lung metastasis, and peritoneal metastasis. Right hemicolectomy and sigmoidectomy were performed. Postoperative TS1 was carried out, but the serum carcinoembryonic antigen level was elevated. We started the mFOLFOX6 regimen. He became confused upon treatment after 49 hours. A blood test revealed that his serum ammonia level was 399μg/dL. We diagnosed 5-fluorouracil-induced hyperammonemia. Conservative treatment with high-volume drip infusion and branched -chain amino acid solutions resulted in improvement of his mental status. We changed his chemotherapy to FOLFOX4 a month later. He received the FOLFOX4 treatment without any significant adverse effect.
