Abstract
Therapeutic effect of FU was improved by the combination with orotic acid. This combination exhibited a marked schedule dependency. The most suitable schedule was to give orally 30 mg/kg/day of orotic acid 30 minutes before FU administration. In combination of FU and orotic acid in this schedule, ILS30 was decreased to 2.1 from 3.1 mg/kg/day and the optimal dose was increased to 30 from 20 mg/kg/day. Maximum ILS was also increased to 81 from 54% and the therapeutic ratio was improved to 14 from 5.1.
