Hercessi

See also Warning section.

Drug interactions may change how your medications work or increase your risk for serious side effects. This document does not contain all possible drug interactions. Keep a list of all the products you use (including prescription/nonprescription drugs and herbal products) and share it with your doctor and pharmacist. Do not start, stop, or change the dosage of any medicines without your doctor's approval.

Trastuzumab is very similar to trastuzumab deruxtecan, trastuzumab emtansine, and trastuzumab-hyaluronidase. Do not use a trastuzumab deruxtecan, trastuzumab emtansine, or trastuzumab-hyaluronidase product while using a trastuzumab product.

Lab and/or medical tests (such as heart function, complete blood count, blood pressure) should be done before you start using this medication and while you are using it. Keep all medical and lab appointments.

If someone has overdosed and has serious symptoms such as passing out or trouble breathing, call 911. Otherwise, call a poison control center right away. US residents can call 1-800-222-1222. Canada residents can call 1-844-764-7669.

It is important to get each dose of this medication as scheduled. If you miss a dose, ask your doctor or pharmacist right away for a new dosing schedule.

Not applicable. This medication is given in a hospital or clinic and will not be stored at home.

Your condition can cause complications in a medical emergency. For information about enrolling in MedicAlert, call 1-888-633-4298 (US) or 1-800-668-1507 (Canada).

Trastuzumab may cause serious heart problems, including heart failure. The risk of heart problems is increased if you also use an anthracycline (such as doxorubicin). Your doctor may stop treatment with this medication if heart problems occur. Tell your doctor right away if you have any symptoms of heart failure (such as shortness of breath, swelling ankles/feet, unusual tiredness, unusual/sudden weight gain).

Infusion reactions and lung problems (possibly fatal) may happen during the infusion of this drug and for up to 24 hours afterward. Your doctor may prescribe other medications (such as acetaminophen, diphenhydramine) before each treatment to help prevent these side effects. Tell your doctor right away if you have any symptoms of infusion reactions or lung problems such as fever, chills, flushing, headache, nausea/vomiting, shortness of breath, cough, dizziness, or weakness. Your doctor may give you other medications to help with these side effects or may stop your treatment for some time.

Trastuzumab can cause serious (possibly fatal) harm to an unborn baby if used during pregnancy. Discuss the use of reliable forms of birth control with your doctor.

See also Warning section.

Redness or irritation at the injection site may occur. Diarrhea, muscle/joint/back pain, stomach/abdominal pain, headache, trouble sleeping, nausea, vomiting, mouth sores, and loss of appetite may also occur. Nausea and vomiting can be severe. In some cases, your doctor may prescribe medication to prevent or relieve nausea and vomiting. Eating several small meals, not eating before treatment, or limiting activity may help lessen some of these effects. If any of these effects last or get worse, tell your doctor or pharmacist promptly.

Remember that this medication has been prescribed because your doctor has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.

Tell your doctor right away if you have any serious side effects, including: bone pain, numbness/tingling, mental/mood changes, fast/irregular heartbeat, easy bruising/bleeding, chest pain.

This medication may raise your blood pressure. Check your blood pressure regularly and tell your doctor if the results are high.

This medication may lower your ability to fight infections. This may make you more likely to get a serious (rarely fatal) infection or make any infection you have worse. Tell your doctor right away if you have any signs of infection (such as sore throat that doesn't go away, fever, chills).

Trastuzumab can commonly cause a rash that is usually not serious. However, you may not be able to tell it apart from a rare rash that could be a sign of a severe reaction. Get medical help right away if you develop any rash.

A very serious allergic reaction to this drug is rare. However, get medical help right away if you notice any symptoms of a serious allergic reaction, including: rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, trouble breathing.

This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.

In the US -

Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088 or at www.fda.gov/safety/medwatch-fda-safety-information-and-adverse-event-reporting-program.

In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.

This medication is given by injection into a vein by a health care professional. It is given as directed by your doctor, usually once every week or once every 3 weeks. This medication is given over 30 to 90 minutes.

The dosage is based on your medical condition, response to treatment, weight, and other medications you may be taking. Be sure to tell your doctor and pharmacist about all the products you use (including prescription drugs, nonprescription drugs, and herbal products).

Use this medication regularly to get the most benefit from it. To help you remember, mark your calendar with a reminder.