Lapatinib Dosage
This dosage information may not include all the information needed to use Lapatinib safely and effectively. See additional information for Lapatinib.
The information at Drugs.com is not a substitute for medical advice. ALWAYS consult your doctor or pharmacist.
Usual Adult Dose for:
Additional dosage information:
Usual Adult Dose for Breast Cancer
HER2 Positive Metastatic Breast Cancer:
Initial dose: 1250 mg (5 tablets) orally once daily on days 1 through 21 continuously in combination with capecitabine
If a daily dose is missed, the patient should not double the dose the next day.
Treatment should be continued until disease progression or unacceptable toxicity occurs.
Hormone Receptor Positive, HER2 Positive Metastatic Breast Cancer:
Recommended dose: 1,500 mg orally once daily continuously in combination with letrozole.
The dose of lapatinib should be once daily (6 tablets administered all at once).
For lapatinib in general:
Lapatinib should be taken at least one hour before or one hour after a meal. Lapatinib should be taken once daily. The dose of lapatinib should not be divided.
Renal Dose Adjustments
Data are not available regarding renal dose adjustments. However, renal impairment is unlikely to affect the pharmacokinetics of lapatinib given that less than 2% of an administered dose is eliminated by the kidneys.
Liver Dose Adjustments
Patients with severe hepatic impairment (Child-Pugh Class C) should have their lapatinib dose reduced. A dose reduction to 750 mg/day in patients with severe hepatic impairment is predicted to adjust the area under the curve (AUC) to the normal range and should be considered. However, there is no clinical data with this dose adjustment in patients with severe hepatic impairment.
Dose Adjustments
Lapatinib should be discontinued in patients with a decreased left ventricular ejection fraction (LVEF) that is Grade 2 or greater by NCI Common Terminology Criteria for Adverse Events (NCI CTCAE) and in patients with an LVEF that drops below the lower limit of normal. Lapatinib may be restarted at a reduced dose (1000 mg/day) after a minimum of two weeks if the LVEF recovers to normal and the patient is asymptomatic.
Discontinuation or interruption of dosing with lapatinib may be considered when patients develop greater than or equal to Grade 2 NCI CTC toxicity and can be restarted at 1250 mg/day when the toxicity improves to Grade 1 or less. If the toxicity recurs, then lapatinib should be restarted at a lower dose (1000 mg/day).
Precautions
Safety and effectiveness have not been established in pediatric patients (less than 18 years of age).
Dialysis
There are no data on the hemodialysis or peritoneal dialysis clearance of lapatinib. Hemodialysis would not be expected to be an effective method to enhance the elimination of lapatinib.
