Fam-Trastuzumab Deruxtecan

This information from Lexicomp^® explains what you need to know about this medication, including what it’s used for, how to take it, its side effects, and when to call your healthcare provider.

Brand Names: US

Enhertu

Brand Names: Canada

Enhertu

What is this drug used for?

• It is used to treat cancer.

What do I need to tell my doctor BEFORE I take this drug?

• If you are allergic to this drug; any part of this drug; or any other drugs, foods, or substances. Tell your doctor about the allergy and what signs you had.
• If you are breast-feeding. Do not breast-feed while you take this drug or within 7 months after you stop taking it.

This drug may interact with other drugs or health problems.

Tell your doctor and pharmacist about all of your drugs (prescription or OTC, natural products, vitamins) and health problems. You must check to make sure that it is safe for you to take this drug with all of your drugs and health problems. Do not start, stop, or change the dose of any drug without checking with your doctor.

What are some things I need to know or do while I take this drug?

• Tell all of your health care providers that you take this drug. This includes your doctors, nurses, pharmacists, and dentists.
• Avoid driving and doing other tasks or actions that call for you to be alert until you see how this drug affects you.
• Have your blood work and heart function checked as you have been told by your doctor.
• This drug may lower the ability of the bone marrow to make blood cells that the body needs. If blood cell counts get very low, this can lead to bleeding problems, infections, or anemia. If you have questions, talk with the doctor.
• You may have more chance of getting an infection. Wash hands often. Stay away from people with infections, colds, or flu.
• You may bleed more easily. Be careful and avoid injury. Use a soft toothbrush and an electric razor.
• If you are 65 or older, use this drug with care. You could have more side effects.
• This drug may affect being able to father a child. Talk with the doctor.
• Talk with your doctor if you plan to freeze or donate sperm while you are taking this drug or after you stop taking it.

What are some side effects that I need to call my doctor about right away?

WARNING/CAUTION: Even though it may be rare, some people may have very bad and sometimes deadly side effects when taking a drug. Tell your doctor or get medical help right away if you have any of the following signs or symptoms that may be related to a very bad side effect:

• Signs of an allergic reaction, like rash; hives; itching; red, swollen, blistered, or peeling skin with or without fever; wheezing; tightness in the chest or throat; trouble breathing, swallowing, or talking; unusual hoarseness; or swelling of the mouth, face, lips, tongue, or throat.
• Signs of infection like fever, chills, very bad sore throat, ear or sinus pain, cough, more sputum or change in color of sputum, pain with passing urine, mouth sores, or wound that will not heal.
• Signs of bleeding like throwing up or coughing up blood; vomit that looks like coffee grounds; blood in the urine; black, red, or tarry stools; bleeding from the gums; abnormal vaginal bleeding; bruises without a cause or that get bigger; or bleeding you cannot stop.
• Signs of electrolyte problems like mood changes; confusion; muscle pain, cramps, or spasms; weakness; shakiness; change in balance; an abnormal heartbeat; seizures; loss of appetite; or severe upset stomach or throwing up.
• Signs of dehydration like dry skin, mouth, or eyes; thirst; fast heartbeat; dizziness; fast breathing; or confusion.
• Dark urine or yellow skin or eyes.
• A burning, numbness, or tingling feeling that is not normal.
• Chest pain.
• Heart failure (weak heart) has happened with this drug. If you have or have ever had heart failure, talk with your doctor. Get medical help right away if you have signs of heart failure like shortness of breath, a big weight gain, coughing up white or pink mucus, fast heartbeat, waking up at night more than normal, or swelling in the arms or legs while you take this drug.

What are some other side effects of this drug?

All drugs may cause side effects. However, many people have no side effects or only have minor side effects. Call your doctor or get medical help if any of these side effects or any other side effects bother you or do not go away:

• Hair loss.
• Change in skin color.
• Mouth irritation or mouth sores.
• Feeling tired or weak.
• Nosebleed.
• Dizziness or headache.
• Signs of a common cold.
• Muscle pain.
• Muscle spasm.
• Arm, back, leg, bone, neck, or stomach pain.
• Constipation.
• Weight loss.
• Diarrhea, throwing up, upset stomach, and decreased appetite are common with this drug. If these happen, talk with your doctor about ways to lower these side effects. Call your doctor right away if any of these effects bother you, do not get better, or are severe.

These are not all of the side effects that may occur. If you have questions about side effects, call your doctor. Call your doctor for medical advice about side effects.

You may report side effects to your national health agency.

You may report side effects to the FDA at 1-800-332-1088. You may also report side effects at https://www.fda.gov/medwatch.

How is this drug best taken?

Use this drug as ordered by your doctor. Read all information given to you. Follow all instructions closely.

• It is given as an infusion into a vein over a period of time.
• Other drugs may be given before this drug to help avoid side effects.

What do I do if I miss a dose?

• Call your doctor to find out what to do.

How do I store and/or throw out this drug?

• If you need to store this drug at home, talk with your doctor, nurse, or pharmacist about how to store it.

General drug facts

• If your symptoms or health problems do not get better or if they become worse, call your doctor.
• Do not share your drugs with others and do not take anyone else’s drugs.
• Keep all drugs in a safe place. Keep all drugs out of the reach of children and pets.
• Throw away unused or expired drugs. Do not flush down a toilet or pour down a drain unless you are told to do so. Check with your pharmacist if you have questions about the best way to throw out drugs. There may be drug take-back programs in your area.
• Some drugs may have another patient information leaflet. If you have any questions about this drug, please talk with your doctor, nurse, pharmacist, or other health care provider.
• This drug comes with an extra patient fact sheet called a Medication Guide. Read it with care. Read it again each time this drug is refilled. If you have any questions about this drug, please talk with the doctor, pharmacist, or other health care provider.
• If you think there has been an overdose, call your poison control center or get medical care right away. Be ready to tell or show what was taken, how much, and when it happened.

Consumer Information Use and Disclaimer

This generalized information is a limited summary of diagnosis, treatment, and/or medication information. It is not meant to be comprehensive and should be used as a tool to help the user understand and/or assess potential diagnostic and treatment options. It does NOT include all information about conditions, treatments, medications, side effects, or risks that may apply to a specific patient. It is not intended to be medical advice or a substitute for the medical advice, diagnosis, or treatment of a health care provider based on the health care provider’s examination and assessment of a patient’s specific and unique circumstances. Patients must speak with a health care provider for complete information about their health, medical questions, and treatment options, including any risks or benefits regarding use of medications. This information does not endorse any treatments or medications as safe, effective, or approved for treating a specific patient. UpToDate, Inc. and its affiliates disclaim any warranty or liability relating to this information or the use thereof. The use of this information is governed by the Terms of Use, available at https://www.wolterskluwer.com/en/know/clinical-effectiveness-terms.

Last Reviewed Date

2024-05-29

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