Tykerb (generic: lapatinib) is a prescription medication used to treat breast cancer. It is used in combination with other medications to treat a certain type of breast cancer that has spread to other parts of the body and that has not responded to other cancer treatments. Tykerb belongs to a group of drugs called kinase inhibitors which work by blocking the action of a certain protein that signals cancer cells to multiply.

This medication comes in tablet form and is taken once daily on an empty stomach.

Common side effects of Tykerb include red, painful hands and feet, diarrhea, rash, and nausea.