Side Effects of Cosentyx: What to Know

Medically Reviewed By Alex Brewer, PharmD, MBA

Cosentyx: Introduction

Cosentyx is a brand-name prescription drug. It’s a type of drug called a monoclonal antibody, and it’s also a biologic. (That means it is made from living cells.)

This medication contains the active drug secukinumab. It comes as a solution and is given by subcutaneous injection.

Cosentyx is approved by the Food and Drug Administration (FDA) to treat the following conditions in certain situations:

Similar to other drugs, Cosentyx may cause side effects. Read below for information about possible side effects, including common, mild, and serious ones.

For a general overview of Cosentyx, including details about its uses, see this article.

If you’d like to try Cosentyx, search here to find a healthcare professional who might prescribe it.

Cosentyx: More common side effects

Some of the side effects of Cosentyx may be more common than others. These side effects may last only a few days to weeks. However, some side effects may last longer or become severe or bothersome. Tell your doctor or pharmacist if you have concerns about any side effects of Cosentyx.

In clinical studies of Cosentyx, these were some side effects that occurred more often:

* For more information about this side effect, see “Cosentyx: Side effects explained” below.

Cosentyx: Mild side effects

Cosentyx can cause mild side effects, some of which are listed below. This list doesn’t include all possible mild side effects. To learn more about side effects of Cosentyx, view the drug’s prescribing information.

Mild side effects of Cosentyx include:

The side effects listed above may last only a few days to weeks. However, some side effects may last longer or become severe or bothersome. Tell your doctor or pharmacist if you have concerns about side effects of Cosentyx.

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 receiving Cosentyx and want to tell the FDA about it, visit MedWatch.

* For more information about this side effect, see “Cosentyx: Side effects explained” below.

Cosentyx: Serious side effects

It’s possible to have serious side effects with Cosentyx. Serious side effects are listed below, but this list may not include all possibilities. To learn more about the side effects of Cosentyx, view the drug’s prescribing information.

Call your doctor right away if you have serious side effects with Cosentyx. However, if you think you’re having a medical emergency or have life threatening side effects, call 911 or your local emergency number.

Serious side effects of Cosentyx and their possible symptoms include:

* For more information about this side effect, see “Cosentyx: Side effects explained” below.
† An allergic reaction is possible after receiving Cosentyx. Specifically, a severe allergic reaction called anaphylaxis occurred in the drug’s clinical studies. For more information, see “Cosentyx: Side effects explained” below.

Cosentyx: Common questions about side effects

Here are some common questions about the drug’s side effects and answers to them. Talk with your doctor if you have other questions about this drug.

Is cancer a side effect of Cosentyx? If so, is it rare?

No, cancer was not reported as a side effect in clinical studies of Cosentyx.

Cosentyx works with your immune system to treat your condition. Your immune system also plays an important role in preventing cancer cells from growing in your body.

There’s not a clear connection between effects of Cosentyx on the immune system and the risk of cancer. However, in theory, it’s possible that there could be an effect.

Talk with your doctor about your risk factors for cancer. They can advise on ways to help reduce your risk.

Does Cosentyx cause weight gain, weight loss, or hair loss?

No, Cosentyx did not cause hair loss or weight changes in people receiving the drug during clinical studies.

If you notice weight gain or weight loss while you’re receiving Cosentyx, it may be due to another side effect of the drug or other cause. For example, diarrhea is a side effect of Cosentyx. And long lasting diarrhea can lead to weight loss.

Additionally, hair loss may occur due to the condition you’re receiving Cosentyx to treat. For instance, if psoriasis affects your scalp, you could have hair loss. And Cosentyx is prescribed to treat plaque psoriasis.

If you’d like, talk with your doctor about healthy ways to manage your weight. And let them know of any concerns you have about hair loss or weight changes.

Are long-term side effects possible with Cosentyx?

It depends.

Some side effects reported in clinical studies of Cosentyx are mild and typically go away on their own. This includes a headache, for example.

Other side effects may require long-term medical care to manage. For instance, a rare side effect of Cosentyx is inflammatory bowel disease. This is a serious autoimmune condition that doesn’t have a cure. It affects your digestive tract. To learn more about this side effect, see the “Cosentyx: Side effects explained” section below.

Talk with your doctor if you have concerns about long-term side effects of Cosentyx.

Can Cosentyx cause neurological side effects?

No, Cosentyx didn’t cause any neurological side effects in clinical studies.

Other drugs that treat psoriasis have rare neurological side effects. (Keep in mind that Cosentyx is prescribed for psoriasis.) For example, Humira may cause nervous system problems. Learn more about Humira’s side effects in this article.

Also, some conditions Cosentyx is prescribed to treat may cause neurological effects. If you receive Cosentyx to treat ankylosing spondylitis, you may have inflammation that can lead to nervous system problems. For example, some people have eye inflammation or joint damage, and this can lead to numbness. Learn more about ankylosing spondylitis in this article.

If you have concerns about neurological side effects, talk with your doctor. They can help you decide on a treatment plan that’s right for you.

Does Cosentyx cause injection site reactions?

Injection site reactions weren’t reported in clinical studies of Cosentyx. However, in general, it’s possible for drugs given by injection to cause reactions at their injection site. And Cosentyx is given by injection.

Injection site reactions can cause symptoms including:

  • bruising
  • inflammation
  • discoloration
  • bleeding
  • warmth
  • swelling

You can reduce your risk of an injection site reaction by carefully following injection instructions for Cosentyx. (You may either give yourself Cosentyx injections or receive them from a healthcare professional.)

If you have a mild injection site reaction, it may help to place a cold compress over the area. If your reaction is severe or lasts a long time, call your doctor.

Will I have withdrawal symptoms if I stop receiving Cosentyx?

Probably not. Cosentyx did not cause withdrawal symptoms in clinical studies. (Withdrawal symptoms occur when a drug that your body is dependent upon is stopped. With dependence, your body needs the drug in order to function as usual.)

However, your condition may worsen after you stop receiving Cosentyx. For example, if you were receiving the drug to manage psoriasis, your symptoms may come back or worsen.

If you want to stop receiving Cosentyx because of a side effect or desire to switch to another drug, talk with your doctor first. They can recommend how to safely stop receiving this medication.

Cosentyx: Side effects explained

Here’s detailed information about some of the side effects of Cosentyx.

Headache

Headache was a rare side effect in clinical studies of Cosentyx in adults with psoriatic arthritis. Headache wasn’t reported in people receiving Cosentyx for other conditions.

Keep in mind that some people get headaches frequently. So the reports of headaches during Cosentyx treatment may or may not have been due to the drug. Additionally, headaches can be a symptom of some of the conditions Cosentyx treats.

What to do

Headaches that are mild will typically go away on their own. If you have a very painful headache that comes on suddenly, call your doctor right away.

If you get headaches frequently, over-the-counter (OTC) pain relievers may help. However, be sure to check with your doctor or pharmacist before taking any OTC drugs. They can ensure you don’t take anything that interacts with your other medications.

Rash

Rash was a rare side effect in clinical studies of Cosentyx. The type of rash reported was urticaria, which is also called hives. Hives are welts on the skin that usually itch. They can be small or large.

Hives can sometimes be a sign of a more serious allergic reaction. To learn about other symptoms of an allergic reaction, see the “Allergic reaction” section below.

Hives may take days or weeks to go away.

What to do

Hives can be very uncomfortable. You can soothe itchiness from hives with:

  • topical creams such as cortisone cream
  • oral antihistamines, such as loratadine (Claritin) or diphenhydramine (Benadryl)

It may help to wear soft fabrics that don’t irritate your skin. You can also try a cool compress to help temporarily relieve itching.

If your hives are happening because of an allergic reaction, including that of anaphylaxis, this is a medical emergency. If you think your symptoms are due to an allergy, call your doctor right away or go to your nearest emergency room.

Inflammatory bowel disease

Inflammatory bowel disease (IBD) was a rare side effect in clinical studies of Cosentyx. IBD is a term that includes two conditions: ulcerative colitis and Crohn’s disease.

In some cases, Cosentyx caused a flare of IBD symptoms in people who already had the condition. In other cases, people receiving Cosentyx had their first occurrence of IBD while taking the drug.

IBD is an autoimmune condition. With this type of condition, your immune system mistakenly attacks healthy cells in your body. Crohn’s disease can affect any part of your digestive system, but ulcerative colitis only affects the large intestine.

Symptoms of inflammatory bowel disease include:

  • weight loss
  • fatigue
  • abdominal pain and bloating
  • diarrhea or constipation
  • blockage in your large intestine
  • blood in your stool

People often have more than one autoimmune condition. Some of the conditions Cosentyx treats are autoimmune ones. So you may be affected by IBD because of your other health condition.

What to do

Several treatment options are available for IBD. Most of these will be prescribed by your doctor. Some examples are:

  • prednisone (Rayos)
  • sulfasalazine (Azulfidine)
  • methotrexate (Rasuvo, Trexall, others)
  • infliximab (Remicade)

Additionally, your doctor may recommend surgery as a treatment for IBD.

If you have symptoms of IBD while receiving Cosentyx, talk with your doctor. They can determine if you have IBD. And they’ll recommend a treatment plan that’s right for you to help relieve your symptoms.

Low white blood cell levels

Low white blood cell levels were reported as a rare side effect in clinical studies of Cosentyx.

In these studies, low white blood cell levels didn’t appear to result in serious infections. And in all cases, this side effect either went away on its own or responded to treatment.

White blood cells help your body fight off germs. So if your white blood cell level is low, you’re more likely to develop an infection. Symptoms of infection will vary, but they may include:

  • inflamed gums
  • fever or chills
  • abdominal pain
  • cough
  • ear discomfort
  • sinus pain or pressure
  • slow-healing wounds

Your doctor can tell if you have low white blood cells by ordering a certain blood test.

What to do

If you have a low level of white blood cells, your doctor may have you pause or stop Cosentyx treatment. They may have you restart the drug when your white blood cell level returns to usual.

In severe cases, this condition can be treated by stimulating your bone marrow to make more white blood cells.

Talk with your doctor about ways to help decrease your risk of infection while you are receiving Cosentyx.

Common cold

Nasopharyngitis, also called the common cold, was a frequent side effect in clinical studies of Cosentyx.

Cosentyx lowers your body’s ability to fight off infection. So you may have a higher risk of colds while receiving this drug.

The common cold is typically caused by a virus. Symptoms include:

  • runny nose
  • sore throat
  • sneezing
  • cough
  • watery eyes
  • tiredness
  • headache
  • fever

What to do

If you have cold symptoms, keep track of your symptoms in case they become more serious. For example, if you have trouble breathing or chest pain, let your doctor know.

There’s no cure for the common cold. That said, you can help your body fight off the cold and get better. To do this, ensure you’re getting plenty of sleep, hydration, and nutritious food. You can also take certain medications to relieve pain and reduce fever. Be sure to talk with your doctor before taking any cold medications, though.

Ask your doctor or pharmacist for more tips on how to take care of your body while you recover from a cold. If your cold doesn’t go away, your doctor may adjust your Cosentyx dosage.

Allergic reaction

As with most drugs, some people can have an allergic reaction after receiving Cosentyx.

A more severe allergic reaction is rare but possible. Specifically, a severe allergic reaction called anaphylaxis occurred in the drug’s clinical studies.

Possible symptoms of mild and serious allergic reactions are listed in the table below.

Mild allergic reaction symptoms Serious allergic reaction symptoms
• itching trouble breathing
rash • swelling in your throat or mouth
flushing • swelling under your skin, possibly in your hands, feet, lips, or eyelids

If you have an allergic reaction to Cosentyx, call your doctor right away. This is important to do because the reaction could become severe.

However, if you’re having a medical emergency or your symptoms feel life threatening, call 911 or a local emergency number.

Cosentyx: Precautions

Be sure to talk with your doctor about your health history before you receive Cosentyx. This drug may not be the right treatment option for you if you have certain medical conditions or other factors that affect your health.

The conditions and factors to consider include those described below.

Recurrent or serious infection. Cosentyx may increase your risk of infection. If you already have an infection that won’t go away, Cosentyx could make it worse. Talk with your doctor if you recently had a serious infection, such as a skin infection that didn’t respond to antibiotics, or toxic shock syndrome. Your doctor can recommend if it’s safe for you to receive Cosentyx.

Inflammatory bowel disease (IBD). In rare cases, Cosentyx may cause a flare of ulcerative colitis or Crohn’s disease. These two conditions are both called IBD. Cosentyx was also reported to cause new cases of IBD. If you already have one of these conditions, talk with your doctor about whether Cosentyx is the right drug for you.

Tuberculosis (TB). You will get tested for TB before you start receiving Cosentyx. Because Cosentyx decreases your body’s ability to fight off infection, it could reactivate a latent tuberculosis infection. (With latent TB, you have TB in your body, but it’s not causing symptoms. Reactivation means the TB becomes active again and causes symptoms.) If you have TB, talk with your doctor about whether Cosentyx is the right medication for you.

Live vaccines. Cosentyx may change the way your body responds to certain vaccines. If you are not up to date on your vaccinations, be sure to talk with your doctor about this before starting Cosentyx. You may have to get live vaccines before you start this drug. (Live vaccines contain a live but weakened form of the germ they’re meant to protect you from.)

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

Latex allergy. If you are allergic to latex or rubber, you may react to the latex cap on Cosentyx needles. Talk with your doctor about receiving Cosentyx from vials. That said, you may have to have injections of this form of the drug from a caregiver or healthcare professional.

Consuming alcohol during Cosentyx treatment

Alcohol does not interact with Cosentyx.

However, both alcohol and Cosentyx decrease your body’s ability to fight off infection. So if you consume alcohol while receiving this drug, your risk of infection may be further increased.

If you drink alcohol, talk with your doctor about whether it’s safe to drink while you’re receiving Cosentyx.

Pregnancy and breastfeeding during Cosentyx treatment

Cosentyx has not been studied much in pregnant or breastfeeding people.

Animal studies haven’t shown a risk of congenital anomalies (also known as birth defects) with Cosentyx. However, it’s important to note that animal studies don’t always predict how a medication will affect people.

If you are planning to become pregnant or breastfeed, talk with your doctor. They can discuss with you the risks and benefits of receiving Cosentyx.

Cosentyx: What to discuss with your doctor

Talk with your doctor or pharmacist to find out more information about Cosentyx. If you have questions about the drug’s side effects, your pharmacist or healthcare professional can help answer them for you.

In addition to discussing Cosentyx with your doctor, you may find the following articles helpful in learning more.

Disclaimer: Healthgrades 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.

Medical Reviewer: Alex Brewer, PharmD, MBA
Last Review Date: 2022 Apr 25
THIS TOOL DOES NOT PROVIDE MEDICAL ADVICE. It is intended for informational purposes only. It is not a substitute for professional medical advice, diagnosis or treatment. Never ignore professional medical advice in seeking treatment because of something you have read on the site. If you think you may have a medical emergency, immediately call your doctor or dial 911.