Herceptin (Trastuzumab) belongs to the group of cancer-fighting medications known as antineoplastics, and in particular to the family of medications known as monoclonal antibodies. It is used in addition to other therapies to treat early stage Breast Cancer and metastatic (cancer that has spread) breast cancer that produce a substance known as HER2 protein. The intravenous (into a vein) form of Herceptin (Trastuzumab)  is also used in combination with other medications to treat metastatic stomach cancer that produces the HER2 protein. Herceptin (Trastuzumab) fights these cancers by seeking out and killing the specific types of cancer cells that carry this protein.

Herceptin (Trastuzumab) may be available under multiple brand names and/or in several different forms. Any specific brand name of Herceptin (Trastuzumab) may not be available in all of the forms or approved for all of the conditions discussed here. As well, some forms of Herceptin (Trastuzumab) may not be used for all of the conditions discussed here.

Your doctor may have suggested Herceptin (Trastuzumab) for conditions other than those listed in these drug information articles. If you have not discussed this with your doctor or are not sure why you are receiving Herceptin (Trastuzumab), speak to your doctor.

The recommended dose and dosing schedule of Herceptin (Trastuzumab) varies according to body size and the type of cancer. It is injected into a vein through a specially prepared site on your skin over 90 minutes. The medication may be injected over 30 minutes if previous doses were tolerated well.

Many things can affect the dose of medication that a person needs, such as body weight, other medical conditions, and other medications. If your doctor has recommended a dose different from the ones listed here, do not change the way that you are receiving Herceptin (Trastuzumab) without consulting your doctor.

Very careful handling of Herceptin (Trastuzumab) is required. It is always given under the supervision of a doctor in a hospital or similar setting with access to sterile equipment for preparation.

Herceptin (Trastuzumab) can cause a number of side effects. It may cause nausea and vomiting, but medications can be given to control this. Your doctor, nurse, or pharmacist can advise you on how to reduce the effects of nausea and vomiting. Keep track of any side effects and report them to your doctor as suggested in the section, "What side effects are possible with Herceptin (Trastuzumab)?"

It is important Herceptin (Trastuzumab) be given exactly as recommended by your doctor. If you miss an appointment to receive Herceptin (Trastuzumab), contact your doctor as soon as possible to reschedule your appointment.

Herceptin (Trastuzumab) is stored in the refrigerator.

Do not dispose of medications in wastewater (e.g. down the sink or in the toilet) or in household garbage. Ask your pharmacist how to dispose of medications that are no longer needed or have expired.

Many medications can cause side effects. A side effect is an unwanted response to a medication when it is taken in normal doses. Side effects can be mild or severe, temporary or permanent.

The side effects listed below are not experienced by everyone who receives Herceptin (Trastuzumab). If you are concerned about side effects, discuss the risks and benefits of Herceptin (Trastuzumab) with your doctor.

The following side effects have been reported by at least 1% of people receiving Herceptin (Trastuzumab). Many of these side effects can be managed, and some may go away on their own over time.

Contact your doctor if you experience these side effects and they are severe or bothersome. Your pharmacist may be able to advise you on managing side effects.

• appetite loss
• changes in nails
• Constipation
• cough
• fatigue
• Fever and chills
• headache
• mild Diarrhea
• nausea
• pain (e.g., muscle and joint pain)
• vomiting

Although most of the side effects listed below don't happen very often, they could lead to serious problems if you do not seek medical attention.

Check with your doctor as soon as possible if any of the following side effects occur:

• diarrhea (more than 4 extra bowel movements a day or any at night)
• fast heartbeat
• itching
• signs of clotting problems (e.g., unusual nosebleeds, bruising, blood in urine, coughing blood, bleeding gums, cuts that don’t stop bleeding)
• symptoms of an infusion reaction (e.g., itching, wheezing, dizziness, fast heart rate)
• symptoms of Anemia (e.g., shortness of breath, tiredness, fast heart rate)
• symptoms of heart problems (e.g., swelling of feet or lower legs, shortness of breath)
• symptoms of infection (e.g., fever or chills, sore throat, cough, redness or swelling, painful urination)
• symptoms of kidney problems (e.g., decreased urine production; drowsiness; shortness of breath; fatigue; swelling of the legs, ankles, or feet)
• symptoms of lung problems (e.g., shortness of breath, wheezing, or coughing)
• trouble swallowing

Seek immediate medical attention if any of the following occur:

• chest pain
• shortness of breath
• symptoms of an allergic reaction (e.g., Hives; dizziness; fast heart rate; difficulty breathing; swelling of the lips, tongue, or throat)
• wheezing

Some people may experience side effects other than those listed. Check with your doctor if you notice any symptom that worries you while you are taking Herceptin (Trastuzumab).

Each vial of sterile, white-to-pale yellow lyophilized powder for IV administration, under vacuum, contains Herceptin (Trastuzumab) 440 mg. Nonmedicinal ingredients: α,α-trehalose dihydrate, L-histidine HCl, L-histidine, and polysorbate 20. Preservative-free. Bacteriostatic water for injection supplied as a 20 mL vial of sterile solution containing 1.1% benzyl alcohol (as antimicrobial preservative), yields 21 mL of a multi-dose solution containing 21 mg/mL of Herceptin (Trastuzumab).

Herceptin (Trastuzumab) should not be used by anyone who is allergic to Herceptin (Trastuzumab), murine proteins, Chinese hamster ovary (CHO) cell proteins, or to any of the ingredients of the medication.

There may be an interaction between Herceptin (Trastuzumab) and any of the following:

• Abatacept
• Adalimumab
• Anakinra
• Azathioprine
• Belimumab
• corticosteroids (e.g., budesonide, Dexamethasone, Hydrocortisone, fluticasone, Prednisone)
• Cyclosporine
• Daclizumab
• eculizumab
• Etanercept
• Fingolimod
• Glatiramer
• Golimumab
• Guselkumab
• Infliximab
• Ixekizumab
• Leflunomide
• mycophenolate
• other medications to treat cancer (e.g., Carboplatin, Cyclophosphamide, Doxorubicin, Ifosfamide, Vincristine)
• Natalizumab
• Ocrelizumab
• Romidepsin
• Sarilumab
• Secukinumab
• siltuximab
• Sirolimus
• Tacrolimus
• Teriflunomide
• Tocilizumab
• Tofacitinib
• Ustekinumab
• Vedolizumab

If you are receiving any of these medications, speak with your doctor or pharmacist. Depending on your specific circumstances, your doctor may want you to:

• stop taking one of the medications,
• change one of the medications to another,
• change how you are taking one or both of the medications, or
• leave everything as is.

An interaction between two medications does not always mean that you must stop taking one of them. Speak to your doctor about how any drug interactions are being managed or should be managed.

Medications other than those listed above may interact with Herceptin (Trastuzumab). Tell your doctor or prescriber about all prescription, over-the-counter (non-prescription), and herbal medications you are taking. Also tell them about any supplements you take. Since caffeine, alcohol, the Nicotine from cigarettes, or street drugs can affect the action of many medications, you should let your prescriber know if you use them.