If you’re receiving chemotherapy for certain types of cancer, your doctor might suggest Udenyca as a treatment option for you.

Udenyca is a prescription drug used to prevent infection in adults and children receiving chemotherapy for non-myeloid cancer. (Non-myeloid cancer is cancer that does not affect your bone marrow.)

If your doctor determines this medication is safe and effective for you, you’ll likely use it for as long as you’re receiving chemotherapy or are at risk of infection.

The active ingredient in Udenyca is pegfilgrastim-cbqv.* (An active ingredient is what makes a drug work.) Udenyca is a biosimilar. This means it’s made from living cells.

Udenyca comes as a liquid solution in a prefilled syringe. It’s given as an injection under your skin.

For more information about Udenyca, including details about its uses, see this in-depth article on the drug.

Like other drugs, Udenyca can cause mild to serious side effects. Keep reading to learn more.

* The reason “-cbqv” appears at the end of the drug’s name is to show that the drug is distinct from similar medications that may be created in the future.

Some people may experience mild to serious side effects during their Udenyca treatment. Examples of Udenyca’s commonly reported side effects include:

  • bone pain*
  • pain in your arms, hands, legs, or feet

This is not a complete list of Udenyca side effects. Continue reading the following sections to learn more about the side effects of this drug.

* To learn more about this side effect, see the “Side effects explained” section below.

Common side effects of Udenyca are usually mild. Examples of mild side effects that have been reported with Udenyca include:

* To learn more about this side effect, see the “Side effects explained” section below.

In most cases, these side effects should be temporary. And some may be easily managed. But if you have any symptoms that are ongoing or bother you, talk with your doctor or pharmacist. And do not stop using Udenyca unless your doctor recommends it.

Udenyca may cause mild side effects other than the ones listed above. See the drug’s prescribing information for details.

Note: After the Food and Drug Administration (FDA) approves a drug, it tracks and side effects of the medication. If you’d like to notify the FDA about a side effect you’ve had with Udenyca, visit MedWatch.

It’s possible that you may have serious side effects from Udenyca, but they’re rare.

Serious side effects that have been reported with Udenyca include:

If you develop serious side effects while using Udenyca, call your doctor right away. If the side effects seem life threatening or you think you’re having a medical emergency, immediately call 911 or your local emergency number.

* To learn more about this side effect, see the “Side effects explained” section below.
† An allergic reaction is possible after using Udenyca. But it’s not clear whether this side effect occurred in studies.

Get answers to some frequently asked questions about Udenyca’s side effects.

How long do Udenyca’s side effects last?

It’s not known how long Udenyca’s side effects may last. But how long they last could vary based on how severe the side effect is.

For example, mild side effects such as bone pain may be temporary, and in most cases, easily managed. Certain serious side effects, such as leukocytosis or a low platelet level may last longer or require close monitoring during your treatment.

In rare cases, it’s also possible to have life threatening side effects from Udenyca, such as spleen rupture and capillary leak syndrome. These require emergency medical attention and may have a longer recovery period.

If you’re concerned about long-term side effects from Udenyca, talk with your doctor.

Could Udenyca cause mood changes, such as anger or anxiety?

No, Udenyca shouldn’t cause mood changes. This wasn’t a reported side effect in studies of Udenyca.

But keep in mind that Udenyca is typically used along with chemotherapy. It’s not uncommon to have mood changes, such as anxiety or depression, during chemotherapy treatment.

If you experience anxiety or other mood changes while using Udenyca, tell your doctor. They’ll help you find ways to manage your mood changes. They can also connect you with mental health resources if needed.

Could I have side effects after stopping Udenyca treatment?

It’s not likely that you’ll start experiencing side effects after stopping your Udenyca treatment. But it is possible to have side effects that continue after your treatment ends.

For example, ruptured spleen is a rare side effect of Udenyca that requires emergency medical treatment. Depending on how severe your condition is, your doctor may recommend that you rest to allow your spleen to heal. This usually takes several weeks or months.

To learn more about this side effect, see the “Side effects explained” section directly below.

Learn more about some of the side effects Udenyca may cause.

Bone pain

Udenyca may cause bone pain in some people. This was a common side effect reported in people using the drug in studies. In most cases, bone pain is mild and temporary.

The cause of bone pain from Udenyca is not known. But scientists believe it may be due to how this drug acts in your body. Udenyca works in the inside part of your bones called the bone marrow. This is where your body makes new blood cells.

It’s thought that as Udenyca stimulates your bone marrow to make more white blood cells, your body releases a substance called histamine. And histamine may cause inflammation (swelling) in your bones, which causes bone pain.

What might help

If you have bone pain during your Udenyca treatment, talk with your doctor. They may recommend over-the-counter (OTC) pain relievers, such as ibuprofen (Advil, Motrin), naproxen (Aleve), or acetaminophen (Tylenol). They might also have you take an antihistamine, such as loratadine (Claritin).

Be sure to talk with your doctor or pharmacist before taking any OTC medication. They’ll let you know if they’re safe for you to take with your other medications or health conditions.

If you have severe bone pain from Udenyca, tell your doctor right away. They may prescribe stronger medication to help with the pain, or they may stop your Udenyca treatment.

Acute respiratory distress syndrome

In some cases, Udenyca may cause acute respiratory distress syndrome (ARDS). ARDS wasn’t reported during studies of the drug, but the condition has been reported in people using Udenyca since it came on the market.

With ARDS, the air sacs in your lungs fill with fluid. This makes it hard for other organs to get the oxygen they need to work properly.

Symptoms of ARDS include:

What might help

ARDS is a medical emergency. If you have symptoms of this side effect during your Udenyca treatment, call 911 or go to the nearest emergency room right away.

Your doctor will check for symptoms of ARDS during your Udenyca treatment. If you experience ARDS, your doctor will stop your Udenyca treatment.

Ruptured spleen

In some cases, Udenyca can cause a ruptured spleen. An enlarged spleen and a ruptured spleen weren’t reported in studies of Udenyca. But these conditions have been reported in people who took Udenyca since the drug came onto the market.

The spleen, an organ in the upper-left part of your belly, helps your body fight infections. Symptoms of a ruptured spleen include:

  • pain in the upper-left part of your belly
  • pain in the upper-left part of your chest or your left shoulder
  • fainting or feeling lightheaded
  • nausea
  • confusion
  • blurred vision
  • anxiety or restlessness

What might help

A ruptured spleen is a medical emergency. Call 911 or go to the nearest emergency room right away if you have symptoms of a ruptured spleen.

Low level of platelets

In rare cases, Udenyca can cause a low platelet level. (Platelets are cells that help with blood clotting.)

Having a low platelet level may increase your risk of bleeding. Symptoms of a low level of platelets can include:

  • frequent nosebleeds
  • bleeding gums
  • heavier bleeding than usual
  • bleeding that takes longer than usual to stop
  • bruising more easily than usual

What might help

Your doctor will likely check your platelet level regularly during your Udenyca treatment. If your platelets are too low, they may have you stop using this medication.

Let your doctor know right away if you have symptoms of a low platelet level. Depending on how severe your symptoms are, they may temporarily or permanently stop your Udenyca treatment.

Inflammation of the aorta

Udenyca can cause inflammation (swelling or damage) of the aorta. This wasn’t reported in studies of Udenyca. But it was a rare but serious side effect reported in some people using the drug after it came onto the market.

The aorta is the main artery that carries blood from your heart to the rest of your body. Inflammation of the aorta can happen as early as the first week of your Udenyca treatment. Symptoms can include:

  • fever
  • belly pain
  • generally feeling unwell
  • back pain

What might help

Tell your doctor right away if you experience symptoms of inflammation of the aorta. Your doctor will likely have you stop using Udenyca, and they can discuss other treatment options with you.

Allergic reaction

Like most drugs, Udenyca can cause an allergic reaction in some people. But it’s not clear whether this side effect occurred in studies.

Symptoms can be mild to serious and can include:

  • skin rash
  • itchiness
  • flushing (temporary warmth, redness, or deepening of skin color)
  • swelling under your skin, usually in your eyelids, lips, hands, or feet
  • swelling of your mouth, tongue, or throat, which can make it hard to breathe

What might help

If you have mild symptoms of an allergic reaction, such as a mild rash, call your doctor right away. They may suggest a treatment to manage your symptoms. Examples include:

  • an antihistamine you take by mouth, such as Benadryl (diphenhydramine)
  • a product you apply to your skin, such as hydrocortisone cream

If your doctor confirms you’ve had a mild allergic reaction to Udenyca, they’ll decide if you should continue using it.

If you have symptoms of a severe allergic reaction, such as swelling or trouble breathing, call 911 or your local emergency number right away. These symptoms could be life threatening and require immediate medical care.

If your doctor confirms you’ve had a serious allergic reaction to Udenyca, they may have you switch to a different treatment.

Keeping track of side effects

During your Udenyca treatment, consider taking notes on any side effects you’re having. You can then share this information with your doctor. This is especially helpful when you first start taking new drugs or using a combination of treatments.

Your side effect notes can include things such as:

  • what dose of the drug you were taking when you had the side effect
  • how soon you had the side effect after starting that dose
  • what your symptoms were
  • how it affected your daily activities
  • what other medications you were taking
  • any other information you feel is important

Keeping notes and sharing them with your doctor will help them learn more about how Udenyca affects you. They can then use this information to adjust your treatment plan if needed.

Udenyca may not be right for you if you have certain medical conditions. This is known as a drug-condition interaction. Other factors may also affect whether Udenyca is a good treatment option for you.

Talk with your doctor about your health history before starting Udenyca. Factors to consider include those described below.

Sickle cell disease. If you have sickle cell disease (SCD), treatment with Udenyca could make your condition worse. Sickle cell crisis (a possibly life threatening condition) can occur in people receiving Udenyca who have a kind of SCD called sickle cell anemia. Before starting Udenyca, let your doctor know if you have SCD. They’ll decide if Udenyca is safe for you to use.

Allergic reaction. If you’ve had an allergic reaction to Udenyca or any of its ingredients, your doctor will likely not prescribe Udenyca. Ask them what other medications are better options for you.

Bleeding problems. Udenyca can lower your platelet level, which may lead to bleeding problems. If you already have bleeding problems, Udenyca may worsen your condition. If you have bleeding problems, talk with your doctor before starting treatment with Udenyca.

Certain cancers. Udenyca may cause tumor growth in people with cancer that affects the bone marrow. Due to this risk, your doctor may prescribe a treatment other than Udenyca if you have bone marrow cancer. Udenyca may also cause cancers of the blood or bone marrow, such as myelodysplastic syndrome or acute myeloid leukemia in people with lung cancer or breast cancer. If you have these kinds of cancer and are using Udenyca, your doctor will monitor you for symptoms of these cancers during your treatment.

Alcohol and Udenyca

There are no known interactions between alcohol and Udenyca. But keep in mind that Udenyca is used with chemotherapy, and alcohol can interact with some chemotherapy drugs.

Alcohol may also worsen certain side effects from chemotherapy, including mouth sores, dry mouth, and diarrhea.

If you drink alcohol, talk with your doctor to learn how much (if any) may be safe to consume with your treatment plan.

Pregnancy and breastfeeding while using Udenyca

It’s not known whether Udenyca is safe to use while pregnant. But Udenyca is typically used with chemotherapy, and most chemotherapy drugs are not safe to use during pregnancy.

If you’re pregnant or planning a pregnancy, talk with your doctor about your treatment options.

It’s also not known whether Udenyca is safe to use while breastfeeding. But Udenyca is typically used with chemotherapy, and most chemotherapy drugs are not safe to use while breastfeeding. If you’re breastfeeding or planning to do so, talk with your doctor before using Udenyca.

Common side effects of Udenyca are typically mild and temporary. But in rare cases, it’s possible to have serious side effects from this medication. Having a conversation with your doctor about the side effects of Udenyca before you start treatment can help you manage any side effects from this drug.

Here are examples of questions to ask your doctor:

  • Is my risk of bone pain higher right after my dose of Udenyca?
  • How do the side effects of Udenyca compare with those of Neupogen (filgrastim)?
  • Can Udenyca cause weight loss?
  • Do I have a higher risk of side effects if I have kidney problems?

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.