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Cancer Treatment Centers of America

Trastuzumab (Herceptin®)


Brand Name: Herceptin®

Trastuzumab is used in the treatment of breast cancer and stomach cancer.

Trastuzumab is in a class of drugs called monoclonal antibodies. Some types of breast and stomachcancer contain an excess amount of a protein called HER2, which the malignant cells require to grow and multiply. Trastuzumab attaches to cells that contain HER2, stopping or slowing the spread of cancer. For this reason, trastuzumab is only used to treat patients with breast cancer that tests positive for HER2, which accounts for about 20–30% of all breast cancers.

This medication is given as a slow injection into a vein (infusion). Usually, each infusion of trastuzumab takes about 90 minutes and is given once per week. If this dose is tolerated well, smaller infusions may be given over about 30 minutes. When trastuzumab is being used to prevent the return of breast cancer, rather than to eliminate it from the body, it may be given once every 3 weeks, or once per week alongside chemotherapy and then once every 3 weeks. The exact dose and duration of treatment may vary depending on several factors, including the type of cancer being treated, how well the medication is working, how well your body is tolerating the drug, and what other medications you are taking. Your doctor will recommend the approach that is best for you.

Trastuzumab side effects

To prevent problematic interactions between trastuzumab and other drugs, be sure to tell your doctor if you are allergic to any medications, and what other medications and supplements you are currently taking. You should also inform your doctor if you have or ever had a liver tumor, liver disease, or kidney disease, if you are pregnant or planning to become pregnant, or if you are breastfeeding. If you have dental work and/or surgery during treatment, be sure to tell your doctor and/or dentist that you are taking trastuzumab.

Trastuzumab may cause heart and/or lung problems. Tell your doctor if you have or ever had heart or lung disease.

Possible side effects may include:

  • Diarrhea
  • Constipation
  • Stomach pain
  • Heartburn
  • Loss of appetite
  • Back, bone, joint, or muscle pain
  • Difficulty sleeping
  • Excessive tiredness
  • Pale skin
  • Hot flushes
  • Numbness, burning, or tingling in the arms, hands, feet, or legs
  • Changes in the appearance of nails
  • Acne
  • Nosebleed
  • Depression

Some of trastuzumab’s side effects can be serious. Call your doctor immediately if you experience any of these symptoms:

  • Sore throat, fever, chills or other signs of infection
  • Cough
  • Shortness of breath
  • Swelling of arms, hands, feet, ankles or lower legs
  • Weight gain of more than 5 pounds in 24 hours
  • Dizziness
  • Fast, irregular, or pounding heartbeat
  • Difficulty breathing or swallowing
  • Hives, itching, rash
  • Nausea and/or vomiting
  • Tightening of the throat

Please note that this is not a comprehensive list. Patients may experience additional effects not mentioned above.

At Cancer Treatment Centers of America (CTCA), your team of cancer experts will explain each of the side effects of trastuzumab with you in detail, as well as the side effects and expectations of all other medications planned as part of your individualized treatment plan.

Trastuzumab for cancer treatment

Trastuzumab is approved by the FDA for the following:

  • Treatment of HER2-overexpressing breast cancer
  • Treatment of HER2-overexpressing metastatic stomach or gastroesophageal junction adenocarcinoma

At CTCA, our integrative approach to cancer treatment works to fight your disease on all fronts and ensures that you remain at the center of everything we do. We encourage participation from both you and your family to make certain you are comfortable with all decisions made regarding your treatment.

The information provided here is for educational purposes only. In no way should it be considered as offering medical advice. Cancer Treatment Centers of America assumes no responsibility for how this material is used. Please check with a physician if you suspect you are ill. Also note that while Cancer Treatment Centers of America frequently updates its contents, medical information changes rapidly. Therefore, some information may be out of date.