Soliris (eculizumab) is a prescription drug used to treat certain rare autoimmune conditions. Soliris can cause side effects that range from mild to serious. Examples include headache and back pain.

Specifically, Soliris is used in adults to treat:

Soliris is also used to treat atypical HUS in children ages 2 months and older.

Note: Soliris is not used to treat HUS caused by Escherichia coli (E.coli) infection of the digestive system.

Soliris is a biologic drug, which means it’s made from living cells. It contains the active ingredient eculizumab. Soliris comes as an intravenous (IV) infusion (an injection into a vein given over time) by a healthcare professional.

Keep reading to learn about common, mild, and serious side effects Soliris can cause. For a general overview of the drug, including details about its uses, see this in-depth Soliris article.

Soliris has a boxed warning. This is the most serious warning from the Food and Drug Administration (FDA). For details, see the “Side effects explained” section.

Below are some of the more common side effects reported in studies of people receiving Soliris treatment. Side effects can vary depending on what condition the drug is being used to treat.

More common side effects in people receiving Soliris for PNH include:

More common side effects in people receiving Soliris for atypical HUS include:

More common side effects in people receiving Soliris for generalized MG include:

  • bone and muscle aches

More common side effects in people receiving Soliris for NMOSD include:

  • dizziness
  • upper respiratory tract infection
  • diarrhea
  • back pain

Mild side effects have been reported with Soliris. These include:

  • headache
  • back pain
  • dizziness
  • diarrhea
  • urinary tract infection (UTI)
  • mild infection, such as the common cold
  • abdominal pain
  • upper respiratory tract infection
  • bone and muscle aches

In most cases, these side effects should be temporary. And some may be easily managed. But if you have symptoms that are ongoing or bothersome, talk with your doctor or pharmacist.

Soliris may cause mild side effects other than those listed above. For an up-to-date list of Soliris’s side effects, see the drug’s prescribing information.

Serious side effects have been reported with Soliris. These include:

If you develop serious side effects during Soliris treatment, 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.

Note: After the 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 Soliris, visit MedWatch.

ALLERGIC REACTION

For some people, Soliris can cause an allergic reaction.

In general, symptoms of an allergic reaction can be mild or serious.

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 and can determine whether you should continue Soliris treatment.

If you have symptoms of a severe allergic reaction, such as swelling or difficulty 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 Soliris, they may have you switch to a different treatment.

Get answers to some frequently asked questions about side effects of Soliris.

Are there long-term side effects of Soliris?

Yes, it’s possible but rare for Soliris to cause long-term side effects. Long-term side effects include those that may start at any time during treatment with a drug, even if you’ve been receiving it for a long time. It also includes side effects that may not go away even after you stop receiving the drug.

Examples of long-term side effects reported in Soliris’s studies include:

If you have PNH, your doctor will monitor you for 8 weeks after you stop Soliris for signs of hemolysis (ruptured red blood cells).

If you have atypical HUS, your doctor will monitor you for signs and symptoms of thrombotic microangiopathy for at least 12 weeks.

You could develop serious infections, including meningococcal infection, several months after stopping Soliris treatment.

Talk with your doctor to learn more about possible side effects of Soliris and how long they may last.

Does Soliris cause weight gain or hair loss?

Weight gain was not reported as a side effect of Soliris in the drug’s studies.

Soliris may cause hair loss. This was reported in people with NMOSD receiving Soliris treatment in studies.

If you’re concerned about weight gain or hair loss with Soliris treatment, talk with your doctor. They can provide more information.

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

High blood pressure

High blood pressure was a common but serious side effect reported in studies of people receiving Soliris treatment for atypical HUS.

High blood pressure doesn’t typically cause symptoms, but in severe cases, it may cause symptoms such as:

What might help

If you have concerns about high blood pressure during Soliris treatment, talk with your doctor. They’ll likely monitor your blood pressure closely during treatment and may also have you check it regularly at home.

In some cases, your doctor may prescribe a blood pressure medication to help lower your blood pressure while you’re receiving Soliris treatment.

If you have symptoms of severe high blood pressure, call 911 or seek emergency medical help right away.

Boxed warning: risk of serious meningococcal infection

Soliris has a boxed warning for the risk of serious meningococcal infection.

This infection is caused by meningococcal bacteria and can be severe and even life threatening. Fatal meningococcal infection, including meningitis, occurred in Soliris’s studies. Meningitis usually affects the lining of the brain and spinal cord. It can also spread to other areas of your body and cause sepsis.

Symptoms of meningococcal infection and sepsis include:

What might help

To lower your risk of meningococcal infection, your doctor will recommend updating or getting your meningococcal vaccinations at least 2 weeks before starting Soliris. They typically won’t prescribe Soliris for you if you haven’t received these vaccines. It should be noted that while meningococcal vaccines help lower your risk of meningococcal infection, they don’t eliminate your risk completely.

Soliris is only available through a risk evaluation and mitigation strategy (REMS) program due to the risk of meningococcal infection. A REMS program is used to help make sure Soliris is used safely. Only specially trained and certified healthcare professionals can prescribe and administer this drug. For more information about the Soliris REMS program, talk with your doctor.

If you think you’re experiencing symptoms of a meningococcal infection or sepsis, call your doctor immediately. If you feel your symptoms are life threatening, call 911 or seek emergency medical care right away.

Keeping track of side effects

During your Soliris 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 a new drug or combination of treatments.

Your side effect notes can include things such as:

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

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

Below is important information you should consider before starting Soliris treatment.

Boxed warning: Risk of serious meningococcal infection

Soliris has a boxed warning. This is the most serious warning from the FDA. For details, see the “Side effects explained” section.

Other warnings

Soliris can sometimes cause harmful effects in people with certain conditions. This is known as a drug-condition interaction. Other factors may also affect whether this drug is a good treatment option for you.

Talk with your doctor about your health history before starting Soliris. Be sure to tell them if any of the following factors apply to you:

  • blood cell problems, such as low white blood cell count
  • kidney problems
  • current infection
  • previous allergic reaction to Soliris
  • pregnancy
  • breastfeeding

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.