Drug information of Lapatinib


Drug group:

Treating certain types of advanced or metastatic breast cancer. It is used in combination with another medicine (capecitabine or letrozole). It may also be used for other conditions as determined by your doctor.

Mechanism of effect

Inhibits both epidermal growth factor receptor and human epidermal growth receptor 2–driven tumor cell growth in vitro and in animal models.


Lapatinib is a small molecule and a member of the 4-anilinoquinazoline class of kinase inhibitors


Oral absorption is incomplete and variable. C max occurs approximately 4 h after administration. Binding to albumin and alpha-1 acid glycoprotein is more than 99%. Primarily metabolized by CYP3A4 and CYP3A5, with minor metabolism by CYP2C19 and CYP2C8. The half-life is 24 h with repeated dosing. Elimination is primarily via CYP3A4/5 metabolism, with negligible (less than 2%) renal excretion. Fecal elimination accounts for approximately 27%.


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.


1-Hepatotoxicity, severe and life-threatening, has occurred. The cause of death is uncertain. 2-Monitor for pulmonary symptoms indicative of interstitial lung disease or pneumonitis; evaluate LVEF throughout use; monitor LFTs before initiation of treatment, every 4 to 6 wk during treatment, and as clinically indicated thereafter. 3-children:Safety and efficacy not established.

Points of recommendation

1- Store at 59° to 86°F.(15°-30°C) 2- Instruct patient to inform health care provider if fatigue, palpitations, severe diarrhea, or shortness of breath occurs. 3- Instruct patient to take lapatinib at least 1 h before or after a meal. 4- Advise patients who have heart or liver problems to inform health care provider of their medical condition. 5- Advise patient not to eat or drink grapefruit products while taking lapatinib. 6- Instruct patients to take the dose of lapatinib once daily and not divide the daily dose

Pregnancy level


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