Would you consider using capecitabine in a patient who previously had encephalopathy with 5-FU?

I will offer my anecdote of a patient I've treated with metastatic rectal cancer. When given FOLFIRI/bev, he felt terrible 1-2 days after the 5-FU pump started. 1st cycle, bounced back with time. 2nd cycle, went to the ER and got admitted for encephalopathy, had hyperammonemia and lactic acidosis. Several case reports such as this one have noted this rare side effect of 5-FU treatment related to changes in the TCA cycle and urea cycle for the lactic acidosis and hyperammonemia, respectively.

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5-FU-induced encephalopathy is rare, involving 5.7% of patients treated with high-dose 5-FU chemotherapy. The mechanism of fluorouracil-induced encephalopathy is unclear, likely multifactorial. Two pathogenetic mechanisms have been postulated: 1. Dihydropyrimidine dehydrogenase (DPD) deficiency, in which high concentrations of 5-FU penetrate into CSF, causing acute demyelination of neurons (2.7% of the population has DPD deficiency), 2. Impairment of the ATP-dependent urea cycle resulting in tra...