Enhertu (fam-trastuzumab deruxtecan-nxki) is a prescription drug used to treat certain kinds of cancer. The drug comes as an intravenous (IV) infusion (an injection into a vein given over a period of time). It’s usually given every 3 weeks.
Enhertu is prescribed for use in certain adults to treat:
- breast cancer that can’t be removed with surgery or that has spread to other parts of the body
- non-small cell lung cancer that can’t be removed with surgery or that has spread to other parts of the body*
- stomach cancer or gastroesophageal cancer that has spread to other parts nearby or other areas of the body
Enhertu is a type of drug called an antibody-drug conjugate. This means it contains two active drugs: fam-trastuzumab, which is an HER2 antibody, and deruxtecan-nxki, which is a topoisomerase I inhibitor (a type of chemotherapy). An active ingredient is what makes a drug work.
This article describes the dosages of Enhertu, as well as its strength and how it’s given. To learn more about Enhertu, see this in-depth article.
* Enhertu received
This section covers standard dosage information about Enhertu. Before you start using this medication, your doctor will discuss dosage details and methods of administration specific to your condition.
What is Enhertu’s form?
Enhertu comes as a powder that your doctor will mix with sterile (germ-free) water to make a solution for intravenous (IV) infusion. An IV infusion is an injection into a vein given over a period of time.
What strength does Enhertu come in?
Enhertu comes in one strength of 100 milligrams (mg).
What are the typical dosing schedules for Enhertu?
Enhertu’s dosage is based on your weight. Your doctor will calculate your dosage using your weight in kilograms.* If you have serious side effects from this medication, your doctor may gradually decrease your dose. They will ultimately prescribe the smallest dosage that provides the desired effect.
Before an Enhertu infusion, you might be given medications that can help prevent nausea and vomiting.
The information below describes dosages that are commonly used or recommended. Your doctor will determine the best dosage to fit your needs.
* One kilogram equals about 2.2 pounds (lb).
Dosage for breast cancer
The recommended Enhertu dosage for breast cancer is 5.4 milligrams per kilogram of body weight (mg/kg). You’ll receive the medication once every 3 weeks as an IV infusion.
Dosage for lung cancer
The recommended Enhertu dosage for non-small cell lung cancer is 5.4 mg/kg. You’ll receive the medication once every 3 weeks as an IV infusion.
Dosage for stomach cancer or gastroesophageal cancer
The recommended Enhertu dosage for stomach cancer or gastroesophageal cancer is 6.4 mg/kg. You’ll receive this dose through an IV infusion once every 3 weeks.
Is Enhertu used long term?
Yes, Enhertu is typically used as a long-term treatment. If you and your doctor determine that Enhertu is safe and effective for you, you’ll likely use it long term.
If you have serious side effects from Enhertu, your doctor may lower your dose.
For example, if you’re using Enhertu to treat breast cancer and develop a very low level of platelets (blood cells that help clot your blood), your doctor may decrease your dose. If this happens a second time, your doctor may decrease your dose even more.
To learn more about specific dosage adjustments based on your condition, see Enhertu’s prescribing information.
Depending on how severe your side effects are, you may need to pause your treatment until your symptoms are relieved. If you have severe side effects, your doctor may permanently stop your Enhertu treatment.
Below are answers to some common questions about Enhertu’s dosage.
What is the maximum dose I can take of 100-mg Enhertu?
Your dose of Enhertu is based on your weight in kilograms, so your maximum dose will vary depending on your weight.
If you’re using Enhertu to treat breast cancer or lung cancer, the maximum recommended dose is 5.4 milligrams per kilogram of body weight (mg/kg). If you’re using Enhertu to treat stomach cancer or gastroesophageal cancer, the maximum dose is 6.4 mg/kg.
Your doctor will calculate your dose for you.
Does my Enhertu dosage need to change if I have liver problems?
No, having liver problems typically won’t affect your Enhertu dosage. But your doctor may monitor you more closely during treatment to make sure the drug isn’t causing you harm.
If you have questions about using Enhertu with your liver problem, talk with your doctor.
The dosage of Enhertu your doctor prescribes may depend on several factors. These include:
- the type and severity of the condition you’re using Enhertu to treat
- your weight
- side effects you may have from Enhertu (see “Dosage adjustments” under “What is Enhertu’s dosage?” above)
Enhertu is given as an intravenous (IV) infusion (an injection into your vein given over a period of time) at a doctor’s office or hospital.
Your first infusion will typically last 90 minutes. If you don’t have side effects from the first infusion, your following doses may be given over a period of 30 minutes.
If you have serious side effects during your infusion, your doctor may give you the medication more slowly or stop the infusion.
If you have questions about what to expect during your infusion, talk with your doctor.
It’s important that you keep your appointments for your Enhertu infusions. If you do miss an appointment, contact your doctor’s office as soon as possible to reschedule.
After receiving your missed dose, your doctor will adjust your schedule, so your appointments remain 3 weeks apart.
If you need help keeping track of your appointments, try using a medication reminder. This can include setting an alarm or downloading a reminder app on your phone.
The sections above describe the typical dosages provided by the drug’s manufacturer. If your doctor recommends Enhertu for you, they’ll prescribe the dosage that’s right for you.
Talk with your doctor if you have questions or concerns about your current dosage.
Here are some examples of questions you may want to ask your doctor:
- How long will my Enhertu infusion take?
- If my dose is lowered due to side effects, will I go back to my regular dose if my side effects improve?
- Does my dosage of Enhertu need to change if I’m taking other medications along with it?
To learn more about Enhertu, see these articles:
I know that my doctor might reduce my Enhertu dose may be lowered if I experience certain side effects. Which specific side effects can affect my dose?Anonymous
Side effects that may affect your dose include:
- serious lung problems, such as interstitial lung disease or pneumonitis (see note below)
- low levels of neutrophils (white blood cells that help your body fight infection)
- low levels of platelets (cells that help your blood to clot)
If you experience these side effects, your doctor may stop your Enhertu treatment until your side effects are relieved or until they feel it’s safe to resume your treatment.
If your treatment is resumed, your doctor may adjust your dose based on how severe your side effects were and how long it took for them to be relieved.
Note: Enhertu has a
Disclaimer: Healthline has made every effort to make certain that all information is factually correct, comprehensive, and up to date. However, this article should not be used as a substitute for the knowledge and expertise of a licensed healthcare professional. You should always consult your doctor or another healthcare professional before taking any medication. The drug information contained herein is subject to change and is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. The absence of warnings or other information for a given drug does not indicate that the drug or drug combination is safe, effective, or appropriate for all patients or all specific uses.