Enhertu (fam-trastuzumab deruxtecan-nxki) is a brand-name solution for intravenous infusion prescribed for certain cancers. Enhertu has no known interactions with alcohol, drugs, or supplements. But the drug may interact with certain health conditions, such as pregnancy.

Enhertu is prescribed to treat the following cancers in certain adults:

An interaction occurs when one substance causes another substance to have a different effect than expected.

To learn more about Enhertu’s interactions, keep reading. For additional information about Enhertu, including details about its uses, see this article.

* “HER2” is short for “human epidermal growth factor receptor 2”. The HER2 gene makes a protein that’s found on the surface of cells, where it promotes cell growth.

Enhertu isn’t known to interact with other medications, based on the drug’s clinical trials. However, it’s possible that new interactions may be recognized in the future. For example, a suspected interaction could be reported by people who’ve received Enhertu since it became available.

Before you start treatment with Enhertu, tell your doctor and pharmacist what prescription, over-the-counter, and other medications you take. By sharing this information with them, you may help prevent possible interactions. (To learn whether Enhertu interacts with supplements, herbs, or vitamins, see the “Enhertu and other interactions” section below.)

If you have questions about drug interactions that may affect you, ask your doctor or pharmacist.

There are no known interactions between Enhertu and alcohol.

If you have questions about drinking alcohol while receiving Enhertu, talk with your doctor or pharmacist.

Enhertu may have other interactions, such as with supplements, foods, vaccines, or even lab tests. You’ll find details below. Keep in mind that the following information does not include all other possible interactions with Enhertu.

Enhertu and supplements

It’s possible for drugs to interact with supplements such as vitamins and herbs.

Enhertu and herbs

There are no specific reports of herbs interacting with Enhertu. However, that doesn’t mean herbal interactions won’t occur or be recognized in the future. Because of this, it’s important to check with your doctor or pharmacist before taking any of these products during Enhertu treatment.

Enhertu and vitamins

There are no specific reports of vitamins interacting with Enhertu. However, that doesn’t mean vitamin interactions won’t occur or be recognized in the future. Because of this, you should talk with your doctor or pharmacist before taking any vitamin product with Enhertu.

Enhertu and food

There were no reports of food interactions with Enhertu. If you have questions about eating certain foods during Enhertu treatment, talk with your doctor for additional information.

Enhertu and vaccines

There aren’t any known interactions between Enhertu and vaccines. However, Enhertu works by weakening your immune system.* Vaccines work by exposing your immune system to a certain virus or bacterium. This helps prepare your body to ward off an infection caused by the specific virus or bacterium.

If your immune system is weakened, vaccines may not work as well to protect you from infection. In some cases, certain types of vaccines could even cause you to become sick.

For additional information about Enhertu and vaccines, talk with your doctor or pharmacist. They can also check whether you’re due for any vaccines.

* For details about this, see the “How it works” section in this article.

Enhertu and lab tests

Enhertu isn’t known to interact with any lab tests. If you have concerns about this medication interacting with lab tests, talk with your doctor.


Cannabis (often called marijuana) and cannabis products, such as cannabidiol (CBD), have not been specifically reported to interact with Enhertu. However, as with any drug or supplement, talk with your doctor before using cannabis in combination with Enhertu. The effects of cannabis may affect how well you stick to your Enhertu treatment plan.

Note: Cannabis is illegal at a federal level but is legal in many states to varying degrees.

Certain medical conditions and other factors may increase the risk of interactions with Enhertu. Before you start this drug, be sure to talk with your doctor about your health history. Enhertu may not be the right treatment option for you if you have certain medical conditions or other factors affecting your health.

Health conditions or factors that might interact with Enhertu include:

  • Heart problems. Before starting Enhertu treatment, tell your doctor if you have a heart problem such as heart failure. Enhertu may weaken the left side of your heart, which could worsen your heart problem. Your doctor can advise whether Enhertu is a safe treatment option for you.
  • Allergic reaction. If you’ve had an allergic reaction to Enhertu or any of its ingredients, your doctor will likely not prescribe Enhertu. Receiving the drug could cause another allergic reaction. You can ask them about other treatments that may be better choices for you.
  • Breastfeeding. It’s not known whether it’s safe to receive Enhertu while breastfeeding. There isn’t enough information to determine whether the drug passes into breast milk or what effects Enhertu may have on a child who’s breastfed. To be safe, your doctor may advise you to avoid breastfeeding during Enhertu treatment and for at least 7 months after your last dose. If you’re breastfeeding or planning to, talk with your doctor before starting Enhertu. They can talk with you about treatment options and ways to feed your child.
  • Pregnancy. Enhertu is not safe to receive while pregnant. This drug has a boxed warning* about the risk of harm to a fetus. For details, see “Boxed warnings” at the top of this article.
  • Risk of serious lung conditions. Enhertu has a boxed warning* about the risk of serious lung conditions. For details, see “Boxed warnings” at the top of this article.

* A boxed warning is the most serious warning from the Food and Drug Administration (FDA). A boxed warning alerts doctors and patients about drug effects that may be dangerous.

You can take certain steps to help prevent interactions with Enhertu. Your doctor and pharmacist are key resources, so reach out to them before starting treatment. For example, you should plan to do the following:

  • Let them know if you drink alcohol or use cannabis.
  • Tell them about any other medications you take, as well as any supplements, herbs, and vitamins.
  • Create a medication list, which your doctor and pharmacist can help you fill out.

It’s also important to read the Enhertu label and other paperwork that may come with the drug. The label may have colored stickers that mention an interaction. And the paperwork, sometimes called the medication guide or patient package insert, may contain details about interactions.

If Enhertu doesn’t come with paperwork, you can ask your pharmacist to print a copy. If you need help reading or understanding this information, ask your doctor or pharmacist.

Besides learning about interactions, you may want to find out more about Enhertu. These resources might help:

Disclaimer: Medical News Today 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.