ENCEPHALOPATHY AND HYPERLACTATEMIA AS A COMPLICATION OF 5-FLUOROURACIL TREATMENT

Background. There is a wide spectrum of metabolic and toxic disorders that can cause acute encephalopathy in cancer patients. In routine clinical practice, hypoglycemia, vitamin B1 (thiamine) deficit, fulminant liver failure, uremia, severe hypoand hypernatremia should be primarily excluded. Central neurotoxicity associated with hyperammonemia in patients receiving 5-fluorouracil (5-FU) and oral fluoropyrimidines should be considered in differential diagnosis. In this case, the analysis of the blood acid-base status and the detection of B-type hyperlactatemia can facilitate the diagnosis of the cause of encephalopathy.

Case description. We present two cases of hyperlactatemia and encephalopathy in stage IV cancer patients with continuous infusion of 5-FU via a portable infusion pump.

Conclusion. Diagnosis of the frequent fluoropyrimidin-related adverse effects, such as myelosuppression, anorexia, diarrhea, mucositis, and palm-plantar syndrome, are routine and mastered by an oncologist at the very beginning of his/her professional activity. Specific fluoropyrimidinerelated encephalopathy or hyperlactatemia are difficult to suspect and recognize. We hope our description will be useful to prevent possible diagnostic errors.

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