Fam-Trastuzumab Deruxtecan-nxki (fam - tras-TOOZ-ue-mab de-rux-TEE-kan - nxki)

Treats cancer, including breast, lung, or stomach cancer. Also treats solid tumors.

Brand Name(s):

Enhertu

When This Medicine Should Not Be Used:

How to Use This Medicine:

Injectable

• Your doctor will prescribe your dose and schedule. This medicine is given through an IV placed in a vein. The medicine must be given slowly, so the IV will have to stay in place for at least 30 to 90 minutes.
• You will receive this medicine while you are in a hospital or cancer treatment center. A nurse or other trained health professional will give you this medicine.
• You may also receive other medicines to help prevent nausea and vomiting.
• Missed dose: This medicine needs to be given on a fixed schedule. If you miss a dose, call your doctor, home health caregiver, or treatment clinic for instructions.

Drugs and Foods to Avoid:

Ask your doctor or pharmacist before using any other medicine, including over-the-counter medicines, vitamins, and herbal products.

Warnings While Using This Medicine:

• This medicine may cause birth defects if either partner is using it during conception or pregnancy. Tell your doctor right away if you or your partner becomes pregnant. If you can get pregnant, your doctor may do tests to make sure you are not pregnant before starting treatment. Female patients should use an effective form of birth control during treatment and for 7 months after the last dose. Male patients with female partners should use an effective form of birth control during treatment and for 4 months after the last dose.
• Do not breastfeed during treatment with this medicine and for 7 months after the last dose.
• Tell your doctor if you have kidney disease, liver disease, lung disease, or history of heart disease.
• Medicines used to treat cancer are very strong and can have many side effects. Before receiving this medicine, make sure you understand all the risks and benefits. It is important for you to work closely with your doctor during your treatment.
• This medicine may cause the following problems:
  • Lung problems (including interstitial lung disease or pneumonitis)
  • New or worsening heart failure
• Talk with your doctor before receiving this medicine if you plan to have children. Some male patients who receive this medicine have become infertile (unable to have children).
• This medicine may make you bleed, bruise, or get infections more easily. Take precautions to prevent illness and injury. Wash your hands often.
• Your doctor will do lab tests at regular visits to check on the effects of this medicine. Keep all appointments.

Possible Side Effects While Using This Medicine:

Call your doctor right away if you notice any of these side effects:

• Allergic reaction: Itching or hives, swelling in your face or hands, swelling or tingling in your mouth or throat, chest tightness, trouble breathing
• Bone or muscle pain
• Chest pain, trouble breathing, cold sweat, bluish-colored skin
• Dry mouth, increased thirst, muscle cramps, nausea or vomiting, uneven heartbeat
• Fever, chills, cough, runny or stuffy nose, sore throat, body aches
• Rapid weight gain, swelling in your hands, ankles, or feet
• Unusual bleeding, bruising, tiredness, or weakness

If you notice these less serious side effects, talk with your doctor:

• Constipation, diarrhea, loss of appetite
• Hair loss
• Pain, redness, itching, burning, swelling, or a lump under your skin where the needle is placed

If you notice other side effects that you think are caused by this medicine, tell your doctor

Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088