Drug Interaction Report

MONITOR: Immunosuppressed patients may have diminished response to diagnostic skin test antigens due to suppression of cell-mediated, delayed-type hypersensitivity. Falsely insignificant or false-negative results may occur in such patients, which may include those who have recently received or are receiving immunosuppressive agents, antilymphocyte globulins, alkylating agents, antimetabolites, radiation, some antirheumatic agents, high dosages of corticosteroids or adrenocorticotropic agents (e.g., greater than or equal to 2 mg/kg/day or 20 mg/day of prednisone or equivalent for 14 consecutive days or more), or long-term topical or inhaled corticosteroids.

MANAGEMENT: Clinicians should be aware of the potential for falsely insignificant or false-negative results when administering diagnostic skin test antigens to patients treated with immunosuppressive agents.

ADJUST DOSING INTERVAL: Administration of trifluridine-tipiracil with a standardized high-fat, high-calorie meal has been shown to decrease trifluridine peak plasma concentration (Cmax) as well as tipiracil Cmax and systemic exposure (AUC) by approximately 40% compared to administration in a fasting state in patients with cancer given a single 35 mg/m2 dose. No change in trifluridine AUC was observed.

MANAGEMENT: Based on the observed correlation between increases in the Cmax of trifluridine and decreases in neutrophil counts, trifluridine-tipiracil should be taken within one hour after completion of the morning and evening meals.