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|
|
 lapatinib |
| Tykerb |
Pharmaceutical
company:
GlaxoSmithKline
www.gsk.com |
Pharmacologic classification: kinase inhibitor
Therapeutic classification: antineoplastic
Pregnancy risk category: D
AVAILABLE FORMS
Tablets: 250 mg
INDICATIONS AND DOSAGES
In combination with capecitabine for advanced or metastatic breast cancer in patients whose tumors overexpress HER2 and who have received treatment with an anthracycline, a taxane, and trastuzumab--
Adults: 1,250 mg (five tablets) P.O. once daily on days 1 to 21, at least 1 hour before or 1 hour after a meal. Give in combination with 2,000 mg/m2 capecitabine P.O. daily in two divided doses about 12 hours apart with food or within 30 minutes after food on days 1 to 14. Give in a repeating 21-day cycle.
ADJUST-A-DOSE:
For patients with severe hepatic impairment (Child-Pugh Class C), reduce dosage of lapatinib to 750 mg P.O. daily. For patients with left ventricular ejection fraction (LVEF) dysfunction grade 2 or greater or below the lower limit, discontinue lapatinib. If LVEF returns to normal and patient is asymptomatic after 2 weeks, restart lapatinib at 1,000 mg P.O. daily.
CONTRAINDICATIONS AND CAUTIONS
No known contraindications.
Use cautiously in patients with impaired hepatic function, decreased left ventricular function, prolonged QT interval, or with conditions that prolong QT interval (hypokalemia, hypomagnesemia). Use cautiously in pregnant and breast-feeding women.
INTERACTIONS
Drug-drug.
CYP3A4 inhibitors, such as ketoconazole, itraconazole, clarithromycin, atazanavir, indinavir, nefazodone, nelfinavir, ritonavir, saquinavir, telithromycin, and voriconazole: May increase serum lapatinib levels. Avoid use together.
CYP3A4 inducers, such as dexamethasone, phenytoin, carbamazepine, rifampin, rifabutin, rifapentin, and phenobarbital: May decrease serum lapatinib levels. Titrate lapatinib dose gradually from 1,250 mg P.O. daily up to 4,500 mg P.O. daily, as tolerated.
Drug-herb.
St. John’s wort: May decrease serum lapatinib levels. Discourage use together.
Drug-food.
Grapefruit juice: May increase serum lapatinib levels. Discourage use together.
ADVERSE REACTIONS
CNS: insomnia.
CV: decreased left ventricular function, prolonged QT interval.
GI: diarrhea, nausea, vomiting, dyspepsia, stomatitis.
Hematologic: anemia, THROMBOCYTOPENIA, NEUTROPENIA.
Respiratory: dyspnea.
Skin: palmar-planar erythrodysesthesia, rash, dry skin.
Other: back pain, extremity pain, mucosal inflammation.
Reactions may be common, uncommon, life-threatening,
or COMMON AND LIFE-THREATENING.
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