Fasenra (benralizumab) is a prescription injection that’s used to treat severe eosinophilic asthma in adults and certain children. Fasenra is not known to interact with alcohol, other medications, or supplements.

An interaction can occur because one substance causes another substance to have a different effect than expected. Interactions can also occur if you have certain health conditions.

Fasenra has not been reported to interact with other drugs. However, this doesn’t mean that interactions aren’t possible. New drugs may be developed that could interact with Fasenra.

Because of this, before you start using Fasenra, tell your doctor and pharmacist about any prescription, over-the-counter, or other drugs you take. Sharing this information with them may help prevent possible interactions. (To learn whether Fasenra interacts with herbs or vitamins and supplements, see the “Are there other interactions with Fasenra?” section below.)

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

Certain health conditions or other factors could raise your risk of harm if you take Fasenra. In such cases, your doctor may not prescribe Fasenra for you. These are known as contraindications. Fasenra has one contraindication, which is described below.

If you’ve had an allergic reaction: If you’ve had an allergic reaction to Fasenra or any of its ingredients, your doctor likely won’t prescribe Fasenra for you. This is because using the drug could cause another allergic reaction. You can ask your doctor about other treatments that may be better options for you.

Fasenra is not known to interact with alcohol. But Fasenra and alcohol can cause some similar side effects, such as headache. You may be more likely to experience this side effect if you drink alcohol during your Fasenra treatment.

If you have questions about consuming alcohol while using Fasenra, talk with your doctor or pharmacist.

Fasenra may have other interactions. They could occur with supplements, foods, vaccines, or even lab tests. See below for details. Note that the information below does not include all other possible interactions with Fasenra.

Does Fasenra interact with supplements?

Before you start using Fasenra, talk with your doctor and pharmacist about any herbs or vitamins and supplements you take. Sharing this information with them may help you avoid possible interactions.

If you have questions about interactions that may affect you, talk with your doctor or pharmacist.

Fasenra and herbs

There are currently no reports of Fasenra interacting with herbs. But this doesn’t mean that interactions with herbs won’t be recognized in the future.

For this reason, it’s still important to check with your doctor or pharmacist before taking any of these products while using Fasenra.

Fasenra and vitamins

There are currently no reports of Fasenra interacting with vitamins. But this doesn’t mean that vitamin interactions won’t be recognized in the future.

For this reason, it’s still important to check with your doctor or pharmacist before taking any of these products while using Fasenra.

Does Fasenra interact with food?

There are currently no reports of Fasenra interacting with food. If you have questions about eating certain foods during your treatment with Fasenra, talk with your doctor.

Does Fasenra interact with vaccines or lab tests?

There are currently no reports of Fasenra interacting with vaccines or lab tests. If you have questions about receiving certain vaccines or having lab tests done during your Fasenra treatment, talk with your doctor.

Does Fasenra interact with cannabis or CBD?

There are currently no reports of Fasenra interacting with cannabis (commonly called marijuana) or cannabis products such as cannabidiol (CBD). But as with any drug or supplement, talk with your doctor before using cannabis with Fasenra.

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

Certain medical conditions or other health factors may raise the risk of interactions with Fasenra. Before using Fasenra, talk with your doctor about your health history. They’ll determine whether Fasenra is right for you.

Health conditions or other factors that might interact with Fasenra include:

Parasitic worm infections: If you have a parasitic worm infection, your doctor will likely prescribe medication to treat this before you start Fasenra treatment. Fasenra hasn’t been studied in people with parasitic worm infections. But it’s possible the drug could make it harder for your body to fight these infections.

Pregnancy: It’s not known whether Fasenra is safe to use during pregnancy. If you’re pregnant or planning a pregnancy, talk with your doctor before using Fasenra.

Breastfeeding: It’s not known whether it’s safe to use Fasenra while breastfeeding. The drug may pass into breast milk, but it isn’t known whether the drug may cause side effects in a child who’s breastfed. If you’re breastfeeding or planning to do so, talk with your doctor about your options.

Allergic reaction: If you’ve had an allergic reaction to Fasenra or any of its ingredients, your doctor will likely not prescribe Fasenra. This is because using the drug could cause another allergic reaction. You can ask your doctor about other treatments that may be better choices for you.

Taking certain steps can help you avoid interactions with Fasenra. Before starting treatment, talk with your doctor and pharmacist. Things to discuss with them include:

  • whether you drink alcohol or use cannabis
  • other medications you take, as well as any vitamins, supplements, and herbs (they can also help you fill out a medication list)
  • what to do if you start taking a new drug during your Fasenra treatment

It’s also important to understand Fasenra’s label and other paperwork that may come with the drug. Colored stickers that describe interactions may be on the label. And the paperwork (sometimes called the patient package insert or medication guide) may have other details about interactions. (If you did not get paperwork with Fasenra, ask your pharmacist to print a copy for you.)

If you have trouble reading or understanding this information, your doctor or pharmacist can help.

Using Fasenra exactly as prescribed can also help prevent interactions.

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.