TS-One Dosage/Direction for Use

Usually, the following standard doses are defined as the initial dose (single dose) for adults according to body surface area. TS-ONE is administered twice daily, after breakfast and after the evening meal, for 28 consecutive days, followed by a 14-day rest. This is regarded as one course of the regimen. (See Table 8.)

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The initial dose can be decreased according to the patient's condition. The doses are staged thus: 40 mg, 50 mg, 60 mg. The dose can be decreased by one stage, and the lower limit is 40 mg.
Precautions on Dosage and Administration: When the dose is decreased according to the patient's condition, the following standard doses should be referenced. (See Table 9.)

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If a drug rest period therapeutically needs to be shortened, it should be implemented after confirming that no drug-induced abnormalities in laboratory findings (hematological tests, liver and renal function tests) and no gastrointestinal symptoms occur, i.e., the drug is not problematic in terms of safety. A minimum drug rest period of 7 days must be provided. Also, safety in the case of the shortened drug rest period with inoperable or recurrent breast cancer have not yet been established (there is no clinical data).
To avoid serious adverse reactions such as bone marrow depression and fulminant hepatitis, the patient's condition should be monitored thoroughly by performing laboratory tests (hematological tests, liver and renal function tests) before the start of each course and at least once every 2 weeks during dosing. If any abnormal findings are observed, appropriate measures should be taken, such as prolongation of the drug rest period, dosage reduction according to the previously mentioned standard doses, or discontinuing administration of TS-ONE. Laboratory tests should be performed frequently, particularly when one course of the regimen is conducted (see Pharmacology: Clinical Studies under Actions).
Since basic investigations (rats) have revealed that the bioavailability of oteracil potassium changes when the drug is administered in the fasting state, it is speculated that phosphorylation of fluorouracil is inhibited and that its antitumor effect is reduced, TS-ONE should be administered after meals.
The recommended treatment course for post-operative adjuvant chemotherapy for gastric cancer is one year after surgery. Treatment with TS-ONE beyond one year after surgery has not been studied.