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Trastuzumab (Herceptin)


Generic NameBrand Name

Trastuzumab (Herceptin) is given as a shot into a vein (intravenously).

How It Works

Trastuzumab targets breast cancer cells that make too much of (overexpress) a protein called HER-2, which is found on the surface of some cancer cells. Trastuzumab slows or stops the growth of these cells. Not all breast cancers make this protein.

Trastuzumab is used after surgery and chemotherapy to treat breast cancer that tests positive for HER-2. It is also used to treat metastatic or recurrent HER-2 breast cancer. It may be used by itself or may be combined with other medicines.

Why It Is Used

Trastuzumab slows or stops the growth of breast cancer that overexpresses the HER–2 protein. It is used only to treat this type of breast cancer, which tends to grow faster and is more likely to come back (recur).

Trastuzumab also is used to control breast cancer that has spread (metastasized) in women who have HER-2 breast cancer.

How Well It Works

After HER-2 breast cancer is first treated, trastuzumab treatment lowers the risk of the cancer coming back (recurring). Taking trastuzumab after surgery and chemotherapy is an effective treatment and makes it more likely that a woman will stay cancer-free and live longer.

Trastuzumab is also used to treat HER-2-positive cancer that has recurred or spread (metastasized). It slows HER-2 tumor growth and reduces tumor size.

Side Effects

Fever and chills commonly occur during the first treatment with trastuzumab and become less severe with later treatments. Other possible serious side effects can include difficulty breathing and heart failure.

Less serious side effects may include:

See Drug Reference for a full list of side effects. (Drug Reference is not available in all systems.)

What To Think About

Trastuzumab can cause heart failure if it damages the heart muscle. You will be carefully evaluated for heart disease before and during treatment with this medicine.

Trastuzumab is a powerful treatment for HER-2 breast cancer. The heart risk linked to trastuzumab can also be serious. Talk to your doctor about whether trastuzumab is a good choice for you.

Trastuzumab can cause birth defects. Do not use this medicine if you are pregnant or trying to become pregnant.

Trastuzumab should be given only under the supervision of a medical oncologist.

Complete the new medication information form (PDF)Click here to view a form.(What is a PDF document?) to help you understand this medication.


ByHealthwise Staff
Primary Medical ReviewerSarah Marshall, MD - Family Medicine
Specialist Medical ReviewerDouglas A. Stewart, MD - Medical Oncology
Last RevisedJune 28, 2011

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