In combination with capecitabine, for the treatment of patients with advanced or metastatic breast cancer whose tumours overexpress HER2+/neu (ErbB2+) and who have received prior therapy including anthracycline, taxane, and trastuzumab.
藥理
Lapatinib is a dual tyrosine kinase inhibitor against epidermal growth factor receptors (EGFR) HER1 and HER2. HER1 and HER2 are overexpressed in over 20% of breast tumors, and is a key component in regulating tumor cell growth, proliferation, metastasis, and transformation.
藥動學
Absorption: Incomplete and variable following oral administration; Effects of food: increased systemic exposure; Protein binding: >99% to albumin and alpha1-acid glycoprotein; Lapatinib undergoes extensive metabolism, primarily by CYP3A4 and CYP3A5, and to a lesser extent via CYP2C19 and 2C8 to oxidized metabolites; Elimination half-life: ~24 hours.
禁忌症
specific contraindications have not been determined
1250 mg (i.e. five tablets) once daily continuously (days 1 through 21) in combination with capecitabine 2000 mg/m2/day ORALLY (divided into 2 doses every 12 hours) on days 1 through 14 in a repeating 21 day cycle until treatment progression of unacceptable toxicity. Do not divide the daily dose; doses should be taken once daily. Swallow tablet whole. Do not chew, break, or crush. Lapatinib should be taken at least one hour before, or at least one hour after food. Take capecitabine with food or within 30 min after food.