Effect of ethyldeoxyuridine on 5-fluorouracil-induced neutropenia.

It is supposed that the toxic effect of 5-fluorouracil (5FU) on tumour cells may be increased by pretreatment with ethyldeoxyuridine (EDU). We studied the effect of this combination on neutrophil count in mice. Our present studies demonstrated that the neutropenia induced by 5 x 20 mg/kg 5FU became more severe when each dose of 5FU was preceded by 200 mg/kg EDU.