Recurrent Reversible Stroke-Like Encephalopathy After 5-Fluorouracil (5-FU) Chemotherapy: A Case Report and Literature Review

Background: Case Report: Conclusions: Chemotherapy based on 5-fluorouracil (5-FU) is a well-established treatment for solid cancers, including met-astatic or advanced colon cancer. Despite its efficacy, 5-FU can cause rare but serious adverse events such as acute neurotoxicity, which presents as symptoms similar to stroke. We report the case of a patient who was diagnosed with stage IV colorectal cancer and who underwent chemotherapy with a high dose of 5-FU as part of the FOLFIRI (Folinic Acid, Fluorouracil, Irinotecan) treatment plan. During the seventh, eighth, and ninth cycles of chemotherapy, the patient suffered from severe encephalopa-thy, and the cause of this condition was determined to the 46-hour continuous intravenous infusion of 5-FU, which was part of the FOLFIRI regimen. 5-FU-induced hyperammonemic encephalopathy is a rare but serious adverse event that requires immediate recognition and treatment. The first step in managing this condition is to halt the 5-FU infusion and provide the patient with high volumes of fluid. Although most cases of 5-FU-induced encephalopathy resolve spon-taneously, recurrence is possible if the drug is re-administered to the same patient. Therefore, it is crucial for healthcare providers to closely monitor patients receiving 5-FU chemotherapy and be aware of the signs and symptoms of hyperammonemic encephalopathy. Early intervention can prevent further complications and en-sure the best possible outcome for the patient. It is important to note that while 5-FU-induced hyperammonemic encephalopathy is rare, it highlights the im-portance of closely monitoring patients receiving chemotherapy to identify and treat adverse events prompt-ly. This can help improve patient outcomes and prevent serious long-term complications. © Am J Case Rep, 2023.