Hyperammonemia Secondary to 5-Fluorouracil.

Area of Science:

• Oncology
• Neurology
• Pharmacology

Background:

• 5-fluorouracil (5-FU) is a cornerstone adjuvant chemotherapy for colon cancer.
• Common 5-FU toxicities include myelosuppression and gastrointestinal issues.
• Hyperammonemic encephalopathy is a rare but significant neurologic complication of 5-FU.

Purpose of the Study:

• To report a case of 5-FU-induced hyperammonemic encephalopathy in a colon cancer patient.
• To highlight the clinical presentation and management of this rare adverse event.
• To emphasize the importance of recognizing this toxicity in clinical practice.

Main Methods:

• Case report of a stage IV colon adenocarcinoma patient receiving palliative chemotherapy.
• Clinical observation of altered mental status and laboratory analysis revealing hyperammonemia.
• Discontinuation of 5-FU and supportive care including lactulose, rifaximin, and renal replacement therapy.

Main Results:

• The patient presented with drowsiness and confusion, attributed to significantly elevated ammonia levels (838 μg/dL).
• Neurologic symptoms resolved following 5-FU cessation and comprehensive treatment.
• No other significant radiologic or laboratory abnormalities were found besides elevated ammonia.

Conclusions:

• 5-FU can induce hyperammonemic encephalopathy, presenting as altered mental status.
• Early recognition and discontinuation of 5-FU are vital for managing this rare toxicity.
• Awareness among healthcare providers is essential for timely diagnosis and effective treatment.