If you have certain types of lung cancer, your doctor might suggest Imfinzi (durvalumab) as a treatment option for you.

Imfinzi is a prescription medication that’s used in certain adults with:

Imfinzi comes as a liquid solution that’s given as an intravenous (IV) infusion, which is an injection into a vein over a period of time. You’ll receive Imfinzi infusions at a clinic or in the hospital.

The length of your Imfinzi treatment will depend on the type of cancer you’re using it to treat and how well the drug works for you. People with NSCLC may use Imfinzi for up to 12 months. People with ES-SCLC may use Imfinzi until the drug is no longer effective for them.

Imfinzi is an immunotherapy drug, which means it works with your immune system to attack cancer cells. It belongs to a group of medications called biologics, which are drugs made from living cells.

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

Like other drugs, Imfinzi can cause mild or serious side effects (sometimes called adverse reactions). Keep reading to learn more.

Below are some of the more common side effects reported by people who took Imfinzi in studies. These side effects can vary depending on the condition the drug is being used to treat.

More common side effects in people taking Imfinzi for non-small cell lung cancer include:

More common side effects in people taking Imfinzi for small cell lung cancer include:

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

Imfinzi can cause mild side effects in some people. These side effects can vary depending on the condition Imfinzi is being used to treat.

Examples of mild side effects that have been reported with Imfinzi when used for non-small cell lung cancer include:

Examples of mild side effects that have been reported with Imfinzi when used for small cell lung cancer include:

  • nausea
  • fatigue
  • hair loss*

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

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

Imfinzi may cause mild side effects other than the ones listed above. See the Imfinzi medication guide.

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

In rare cases, some people may experience serious side effects from Imfinzi. Serious side effects that have been reported with Imfinzi include:

  • infusion reactions*
  • immune system side effects, which may cause swelling in your bowels, liver, eyes, heart, or kidneys
  • trouble breathing
  • allergic reaction

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

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

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

Note: Imfinzi is usually given with chemotherapy drugs. The side effects reported in clinical studies occurred in people who received Imfinzi with chemotherapy. So it’s unknown whether Imfinzi or the chemotherapy caused certain side effects. If you have questions, talk with your doctor.

Skin rash

Some people may develop a rash during their Imfinzi treatment. In studies, rash was one of the most common side effects that people taking Imfinzi reported.

In some rare cases, Imfinzi may cause a very serious rash, such as Stevens-Johnson syndrome (SJS) or drug rash with eosinophilia and systemic symptoms (DRESS). These conditions can even be life threatening, so it’s important to treat them right away if they develop. Symptoms may include:

  • fever
  • blistering in your mouth, nose, or eyes
  • blistering rash that’s red, purple, or discolored

What might help

If you develop symptoms of a rash, see your doctor right away. They can recommend creams or other medications to treat it so it doesn’t get worse. They can also determine how serious your rash is.

If you develop a more serious rash, such as SJS or DRESS, you may need to be treated in a hospital. That’s because these conditions can be life threatening. Your doctor may also have you stop using Imfinzi and switch to a different treatment.

If you have questions or concerns about developing a rash during your Imfinzi treatment, talk with your doctor.

Hair loss

Some people may experience hair loss while using Imfinzi. In studies, this was a common side effect reported in people taking Imfinzi along with chemotherapy for small cell lung cancer.

Chemotherapy drugs often cause hair loss. So, it’s not known whether Imfinzi caused the hair loss or whether it was due to the chemotherapy.

In studies, hair loss wasn’t reported in people using Imfinzi for non-small cell lung cancer.

What might help

If you experience hair loss while using Imfinzi that concerns you, talk with your doctor. They may be able to help you determine the cause and the best ways to treat it.

Infusion reactions

In rare cases, Imfinzi may cause infusion reactions. These are allergic-type symptoms that may occur during or after your infusion.

In some cases, these reactions may be serious or even life threatening. Symptoms may include:

  • chills
  • rash or itching
  • trouble breathing
  • dizziness
  • fever
  • pain in your back or neck

What might help

If you experience symptoms of an infusion reaction during or after an infusion, tell your doctor right away. In some cases, these reactions can be serious or even life threatening.

Your doctor may recommend that your current infusion is slowed down or stopped until your symptoms improve. In some cases, your doctor may recommend that you stop your Imfinzi treatment and switch to a different medication.

Cough

Imfinzi may cause a cough in some people. In studies, cough was a common side effect reported in people using Imfinzi.

What might help

If you develop a cough, talk with your doctor right away. They’ll check to make sure your cough isn’t from an immune system condition called pneumonitis (swelling in your lungs). Your doctor can determine the cause of your cough and the best way to treat it.

If you have concerns about developing a cough during your Imfinzi treatment, talk with your doctor.

Allergic reaction

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

Symptoms can be mild or serious and can include:

  • skin rash
  • itchiness
  • flushing (temporary warmth, redness, or deepening of skin color)
  • swelling under your skin, typically 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 an over-the-counter oral antihistamine, such as Benadryl (diphenhydramine), or a topical product, such as hydrocortisone cream, to manage your symptoms.

If your doctor confirms you had a mild allergic reaction to Imfinzi, 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 had a serious allergic reaction to Imfinzi, they may have you switch to a different treatment.

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Keeping track of side effects

During your Imfinzi treatment, consider keeping notes on any side effects you’re having. Then, you can share this information with your doctor. This is especially helpful to do 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 drug you were taking when you had the side effect
  • how soon after starting that dose you had the side effect
  • what your symptoms were from the side effect
  • how it affected your daily activities
  • what other medications you were also taking
  • any other information you feel is important

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

Imfinzi may not be right for you if you have certain medical conditions or other factors that affect your health. Talk with your doctor about your health history before you take Imfinzi. The list below includes factors to consider.

Organ or stem cell transplant. If you’ve recently received or plan to receive an organ transplant or an allogeneic hematopoietic stem cell transplantation, tell your doctor before using Imfinzi. Although rare, it’s possible that Imfinzi may cause your body to attack the transplanted cells or organ. Talk with your doctor about whether Imfinzi is safe for you to use.

Allergic reaction. If you’ve had an allergic reaction to Imfinzi or any of its ingredients, you shouldn’t take Imfinzi. Ask your doctor what other medications are better options for you.

Immune system problems. If you have any immune system problems, such as Crohn’s disease or lupus, tell your doctor before you start Imfinzi. This drug may cause the symptoms of your immune system condition to get worse. Your doctor can determine if Imfinzi is a safe option for you.

Nervous system conditions. Tell your doctor about any conditions you have that affect your nervous system, such as myasthenia gravis or Guillain-Barré syndrome. Taking Imfinzi may make the symptoms of these conditions worse. If you have a nervous system condition, your doctor can determine if it’s safe for you to use Imfinzi.

Alcohol use and Imfinzi

There are no known interactions between Imfinzi and alcohol. But alcohol may make some side effects of Imfinzi worse. Examples of these side effects include nausea and fatigue (lack of energy), and serious conditions such as liver disease.

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

Pregnancy and breastfeeding while taking Imfinzi

Using Imfinzi while pregnant is not recommended. Clinical studies haven’t looked at the drug’s use during pregnancy in humans. But based on the way the medication works and the results of animal studies, it’s believed that Imfinzi can cause harm to a fetus.

Because of this risk, your doctor may recommend that you use birth control during your Imfinzi treatment if you’re able to become pregnant. You’ll also need to use birth control for at least 3 months after your last dose.

Breastfeeding during Imfinzi treatment is not recommended. The drug’s use while breastfeeding hasn’t been studied, so it’s not known what effects the drug may have on a breastfed child. But due to the possible risks, breastfeeding is not recommended during treatment or for at least 3 months after receiving the last dose.

If you’re pregnant or breastfeeding or planning to become pregnant or to breastfeed, talk with your doctor before using Imfinzi.

Imfinzi can be an effective treatment option for certain types of lung cancer. But some people may experience side effects from the drug.

Before starting your Imfinzi treatment, talk with your doctor about your risk for side effects. Here are some questions you may want to ask:

  • How should I treat side effects that I experience from Imfinzi?
  • Which symptoms should I watch for, and when should I contact you?
  • What should I do if I become pregnant while taking Imfinzi?
  • Will my other medical conditions increase my risk for side effects?

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.