Serum concentrations of 5-fluorouracil achieved with nocturnal constant-rate infusion in patients with disseminated cancer

Nocturnal infusion of 5-fluorouracil (FUra) was performed in nine patients with disseminated cancer. Three gastric, three colon and three breast cancer patients were administered 300mg/m2 FUra continuously for 10 h per day from 2100 h to 0700 h for more than 20 consecutive days. In the first three patients, who were treated by drip infusion without the use of a volumetric pump, serum FUra concentrations ranged widely, from 27 to 1370 ng/ml, even though the rate of administration was re-adjusted four times during the night. The last six patients were treated using a volumetric pump, and FUra concentrations in serum ranged from 175 to 378 ng/ml, and displayed no circadian rhythm. Although the dose intensity and area under the curve of FUra in these patients were high, neither myelosuppression nor other side effects were observed.