Tykerb is used together with another medicine called capecitabine (Xeloda) or letrozole (Femara) to treat a certain type of advanced breast cancer that has spread to other parts of the body. It is often given after other cancer medications have been tried without successful treatment of symptoms.
Tykerb may also be used for purposes not listed in this medication guide.
Important information about Tykerb:
Do not use Tykerb if you are pregnant. It could harm the unborn baby.
Before you take Tykerb, tell your doctor if you have heart disease, liver disease, an electrolyte imbalance (low potassium or magnesium), or a personal or family history of Long QT syndrome.
To make sure you can safely take Tykerb, your heart function will need to be checked before you start treatment. Your liver function will need to be checked every 4 to 6 weeks during treatment.
Take Tykerb on an empty stomach. Take this medication for the entire length of time prescribed by your doctor.
Before taking Tykerb
You should not use Tykerb if you are allergic to lapatinib.
To make sure you can safely take Tykerb, tell your doctor if you have any of these other conditions:
an electrolyte imbalance (such as low levels of potassium or magnesium in your blood); or
a personal or family history of “Long QT syndrome.”