Cimzia (certolizumab pegol) is a brand-name subcutaneous injection that’s prescribed to treat several conditions, such as Crohn’s disease. Cimzia can cause mild and serious side effects. One example is skin rash.

Cimzia can cause certain side effects, some of which are more common than others. These side effects may be temporary, lasting a few days to weeks. However, if the side effects last longer than that, bother you, or become severe, be sure to talk with your doctor or pharmacist.

These are just a few of the more common side effects reported by people who took Cimzia in clinical trials:

Since Cimzia is approved to treat many conditions, some of these side effects may only occur in certain people using Cimzia.

* For more information about this side effect, see “Side effect specifics” below.

Mild side effects can occur with Cimzia use. This list doesn’t include all possible mild side effects of the drug. For more information, you can refer to Cimzia’s prescribing information.

Mild side effects that have been reported with Cimzia include:

These side effects may be temporary, lasting a few days to weeks. However, if the side effects last longer than that, bother you, or become severe, be sure to talk with your doctor or pharmacist.

Note: After the Food and Drug Administration (FDA) approves a drug, it tracks side effects of the medication. If you develop a side effect while using Cimzia and want to tell the FDA about it, visit MedWatch.

* For more information about this side effect, see “Side effect specifics” below.

In most cases, side effects of Cimzia are mild. However, in some cases, it’s possible to develop serious side effects from this drug.

Cimzia may cause serious side effects. The list below may not include all possible serious side effects of the drug. For more information, you can refer to Cimzia’s prescribing information.

If you develop serious side effects while using Cimzia, 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.

Serious side effects that have been reported and their symptoms include:

  • Nerve conditions, such as multiple sclerosis. Symptoms can include:
    • dizziness
    • numbness or tingling
    • weakness in your arms or legs
    • changes in vision
  • Low blood cell levels, such as low white blood cells. Symptoms can include:
    • fever
    • bruising easier than usual
    • bleeding that doesn’t stop as quickly as usual
  • Heart failure. Symptoms can include:
    • swelling of your ankles or feet
    • shortness of breath
    • weight gain
  • Hepatitis B virus (HBV) reactivation. Cimzia can reactivate HBV in people who’ve been exposed to the virus in the past and carry the inactive form. Reactivation may cause a hepatitis B infection. Symptoms can include:
  • Lupus-like syndrome (a long-term condition that causes pain and inflammation throughout the body). Symptoms can include:
    • shortness of breath
    • joint pain
    • rash on the cheeks or arms
  • Risk of certain cancers.*
  • Risk of severe infection.*
  • Eye-related side effects.†
  • Severe allergic reaction.‡

* Cimzia has a boxed warning for this side effect. A boxed warning is the most serious warning from the Food and Drug Administration (FDA). To learn more, see the “Side effect specifics” section below.
† To learn more about this side effect, see the “Side effect specifics” section below.
‡ An allergic reaction is possible after using Cimzia. However, this was rarely reported. To learn more, see the “Side effect specifics” section below.

Learn more about some of the side effects that Cimzia may cause. To find out how often side effects occurred in clinical trials, see the prescribing information for Cimzia.

Certain cancers

Cimzia has a boxed warning for the risk of developing certain cancers during treatment. A boxed warning is the most serious warning from the Food and Drug Administration (FDA). The purpose of a boxed warning is to alert doctors and patients about the risks of taking a medication.

This drug may weaken the immune system, which can increase the risk of cancer. Although cancer was not a common side effect of Cimzia, it can still develop. Types of cancer that can develop from Cimzia treatment include lymphoma, leukemia, and skin cancer.

Symptoms can include:

Most people who developed cancer from using Cimzia were also taking other medications that weakened their immune system. This included azathioprine (Azasan).

What you can do

Throughout your treatment with Cimzia, your doctor will monitor your blood using blood tests. They may also check your skin to be sure that there aren’t any symptoms of skin cancer.

If you notice any of the symptoms above, tell your doctor right away. They can help determine what may be causing them.

Severe infection

It’s possible to develop a severe infection during Cimzia treatment. In fact, Cimzia has a boxed warning for the risk of this side effect. A boxed warning is the most serious warning recommended by the FDA. The purpose of a boxed warning is to alert doctors and patients about the risks of taking a medication.

Cimzia may weaken your immune system, which can increase your risk of infection. Mild infections, such as the common cold or a urinary tract infection (UTI), were common during Cimzia treatment. However, more severe infection was not as common.

Examples of serious infections include pneumonia, serious fungal infection, or tuberculosis (TB) returning after Cimzia treatment.

Symptoms may include:

  • fever or chills
  • cough
  • muscle aches
  • shortness of breath
  • weight loss
  • coughing up blood
  • skin sores or painful or warm areas of skin
  • pain or burning while urinating
  • fatigue

Most people who developed a severe infection in clinical trials were also taking drugs that weakened their immune system. Examples of these medications include methotrexate (Trexall) or corticosteroids such as prednisone (Rayos).

What you can do

If you develop symptoms of a severe infection, contact a doctor or go to the hospital right away. It’s possible for a severe infection to become life threatening. However, if the infection is treated immediately, the risk of it becoming severe may decrease.

If you develop a severe infection, your doctor will recommend that you stop Cimzia treatment.

Before you start treatment with Cimzia, your doctor will order a test to be sure that you do not have TB. If the test shows that you have TB, your doctor may recommend a different medication for your condition.

In addition, you can take steps to help prevent infections from occurring. These include washing your hands and staying away from people who are sick.

Injection site reactions

It’s possible to experience injection site reactions with Cimzia. This reaction occurs at the site where you inject your dose of Cimzia. (Cimzia is given as a subcutaneous injection. To learn about how to inject Cimzia, see this article.)

Injection site reactions were common in clinical trials of Cimzia. And as with most injectable medications, if you use a higher dose, the risk of this side effect may increase.

Symptoms of an injection site reaction may include:

  • injection pain
  • skin discoloration
  • bruising
  • swelling

What you can do

If you experience injection site reactions from using Cimzia, tell your doctor. Be sure to inject your Cimzia dose in a different spot each time. This can help decrease your risk of injection site reactions.

If you experience injection site reactions that are severe or bothersome, your doctor may recommend an over-the-counter medication to ease your symptoms. For example, they may recommend taking acetaminophen (Tylenol) if you experience injection site pain.

If you have additional questions about the side effects of Cimzia shots, talk with your doctor or pharmacist.

Hair loss

Hair loss is a possible side effect of Cimzia. However, this was not commonly reported in people using Cimzia in clinical trials.

What you can do

If you notice hair loss during your treatment with Cimzia, tell your doctor. They may recommend ways to reduce the risk of this side effect occurring. For example, your doctor may recommend using an over-the-counter drug such as minoxidil (Rogaine) to help reduce hair loss.

Eye-related side effects

It’s possible to develop eye-related side effects from using Cimzia. Eye-related side effects were not commonly reported in people taking this medication. However, they are still possible.

Cimzia may cause optic neuritis (swelling of the area around your optic nerve). This may cause symptoms such as vision loss or eye pain.

Also, Cimzia may increase the risk of nerve problems such as multiple sclerosis. This condition may cause changes in your vision. Other eye conditions, such as bleeding of the vessels in your eye or uveitis (swelling of the eye), may occur from Cimzia treatment as well.

What you can do

If you notice any eye-related side effects, such as the ones listed above, be sure to tell your doctor right away. They may recommend having an eye exam to determine what may be causing your symptoms.

In some cases, your doctor may recommend that you stop Cimzia treatment and try a different drug for your condition.

Allergic reaction

As with most drugs, Cimzia can cause an allergic reaction in some people. However, this was rarely reported.

Symptoms can be mild or serious and can include:

  • skin rash
  • itching
  • flushing
  • 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 you can do

For mild symptoms of an allergic reaction, call your doctor right away. They may recommend ways to ease your symptoms and determine whether you should keep using Cimzia. However, if your symptoms are serious and you think you’re having a medical emergency, immediately call 911 or your local emergency number.

Cimzia may cause several side effects. Here are some frequently asked questions about the drug’s side effects and their answers.

Should I expect weight gain with Cimzia?

No, you shouldn’t expect weight gain with Cimzia treatment. People taking this medication in clinical trials didn’t report weight gain as a side effect.

However, it’s possible to develop new or worsening heart failure from using Cimzia. A symptom of heart failure is swelling of the legs or ankles, which can lead to sudden weight gain.

If you notice weight gain while you’re using Cimzia, talk with your doctor. They can help determine what may be causing your weight gain and the best way to treat it.

Is itching a side effect of Cimzia?

Itching isn’t a known side effect of Cimzia. In clinical trials, itching wasn’t reported as a side effect.

However, itching is a possible symptom of an allergic reaction. To learn more, see “Side effect specifics” above.

It’s also possible to experience itching from your condition. For example, Cimzia is approved to treat plaque psoriasis, which may cause itching. In addition to plaque psoriasis, doctors may prescribe Cimzia to treat the following conditions in certain people:

(For more details about the approved uses of Cimzia, see this article.)

If you notice itching during your treatment with Cimzia, talk with your doctor. They can help determine what may be causing your itching and the best way to treat it.

Talk with your doctor about any medical conditions that you have before starting treatment with Cimzia. Below are precautions for this drug.

Boxed warnings

This drug has boxed warnings about the risks of certain cancers and severe infection. A boxed warning is the most serious warning from the Food and Drug Administration (FDA). For details, see the “Side effect specifics” section above.

Other precautions

Be sure to talk with your doctor about your health history before you use Cimzia. This drug may not be the right treatment option for you if you have certain medical conditions or other factors that affect your health. These are known as drug-condition or drug-factor interactions. The conditions and factors to consider include:

Active infection. Cimzia may increase your risk of infection, which can be severe. If you have a current infection, using Cimzia can make your infection worse. Your doctor will recommend treating your infection before starting Cimzia treatment.

Lymphoma or other cancers. It’s possible for Cimzia to increase your risk of lymphoma or other types of cancer. If you’ve ever had lymphoma or another cancer, tell your doctor before starting Cimzia treatment. It’s possible for Cimzia to worsen your cancer or increase the risk of it coming back. In this case, your doctor can help determine whether Cimzia is a safe treatment option for you.

Heart failure. Tell your doctor if you have heart failure. This medication may worsen heart failure. Your doctor may monitor your heart more closely during your treatment with Cimzia.

Hepatitis B infection. If you’ve ever had hepatitis B, tell your doctor before starting Cimzia. This drug can reactivate the hepatitis B virus, leading to a hepatitis B infection. Your doctor will likely order a blood test to check for hepatitis B before you start Cimzia treatment. If you have hepatitis B, your doctor can help determine whether Cimzia is a safe treatment option for you.

Allergic reaction. If you’ve had an allergic reaction to Cimzia or any of its ingredients, including rubber or latex, your doctor will likely not prescribe Cimzia. Ask your doctor what other medications may be better options for you.

Nerve conditions. If you have any nerve conditions, such as multiple sclerosis, seizures, or Guillain-Barré syndrome, tell your doctor before starting Cimzia. This medication can lead to nerve conditions and may worsen existing nerve conditions. Your doctor can help determine whether Cimzia is a safe treatment option for you.

Blood conditions. It’s possible for Cimzia to cause low blood cell levels, including low white blood cells. If you have a blood disorder or a condition that causes low blood cell levels, Cimzia may worsen your condition. Your doctor can help determine whether using Cimzia is safe for you.

Alcohol with Cimzia

Cimzia isn’t known to interact with alcohol. However, it’s possible for alcohol to worsen some of the side effects of Cimzia. For example, both Cimzia and alcohol can cause headaches. So the combination of Cimzia and alcohol can increase the risk and severity of headaches further.

In addition, alcohol may make your condition worse. For example, drinking alcohol can worsen the symptoms of plaque psoriasis. (Cimzia is approved to treat plaque psoriasis, among other conditions. For more details about the approved uses of Cimzia, see this article.)

If you drink alcohol, talk with your doctor to determine whether it’s safe for you to drink it while you’re using Cimzia.

Pregnancy and breastfeeding while using Cimzia

It’s not known whether it’s safe to use Cimzia during pregnancy or while breastfeeding.

Currently, there haven’t been enough clinical trials done in pregnant people to determine whether the drug is safe to use during pregnancy. However, two studies show that when pregnant people took Cimzia during the third trimester, developing fetuses were exposed to a very small amount of the drug.

Also, animal studies of Cimzia did not show an increased risk of congenital anomalies (commonly known as birth defects). However, animal studies don’t always indicate what may happen in humans.

It’s important to note that untreated Crohn’s disease and rheumatoid arthritis during pregnancy may increase certain risks, including pregnancy loss. So your doctor will likely recommend treating these conditions during pregnancy.

They’ll also likely recommend signing up for the pregnancy registry for Cimzia. A pregnancy registry is a collection of information about the effects of a drug when it’s taken during pregnancy. The purpose of a pregnancy registry is to help determine whether a drug may be safe to use during pregnancy. To learn more about the registry, call 1-866-626-6847 or view this website.

It’s possible for a small amount of Cimzia to pass into breast milk. In clinical trials, this amount of Cimzia did not cause side effects in children who were exposed to the drug through breast milk.

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

Cimzia may cause side effects. In most cases, these side effects are mild. However, it’s possible to develop serious side effects from this medication, as well.

If you’d like to learn more about Cimzia, talk with your doctor or pharmacist. They can help answer any questions you have about side effects of taking the drug.

Besides talking with your doctor, you can do some research on your own. These articles 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.