フルオロウラシル投与により高アンモニア血症を発症した頭頸部癌の2例

抄録

Hyperammonemia is a serious side effect of 5-fluorouracil (5-FU), but there have been only a few reports of the side effect observed in patients with cancers in the head and neck region. In this report, we describe two cases of hyperammonemia caused by 5-FU administration. Case 1 was a 77-year-old man who received 5-FU + CBDCA (carboplatin) + radiotherapy for supraglottic carcinoma. On day 4 of treatment, he became unconscious and blood tests showed hyperammonemia, which was diagnosed as an adverse effect of 5-FU. 5-FU administration was discontinued, and amino acid preparations, lactulose, kanamycin, and high-dose replacement fluids were administered. Case 2 was a 66-year-old male who received TPF as induction chemotherapy for primary mesopharyngeal carcinoma of the right tonsil, followed by cervical dissection. On day 5 after administration, he became unconscious and blood tests showed hyperammonemia. Amino acid preparations, lactulose, and fluid infusions were administered. In both cases, the hyperammonemia and consciousness level improved after treatment. Possibility of hyperammonemia should be borne in mind in cases who develop impaired consciousness after administration of 5-FU.