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Rilonacept Injection

Why is this medication prescribed?

Rilonacept injection is used to treat cryopyrin-associated periodic syndromes (CAPS; inherited conditions in which the body attacks its own tissues causing inflammation, joint and muscle pain, rash or other skin lesions, fever and chills, eye redness or pain, and fatigue), including familial cold autoinflammatory syndrome (FCAS), and Muckle-Wells syndrome (MWS) in adults and children 12 years of age or older. Rilonacept injection is also used to treat deficiency of interleukin-1 receptor antagonist (DIRA; a disorder in which the body attacks its own tissues causing inflammation and damages bones, nervous system, skin, lungs, liver, and joints) in adults and children who weigh at least 22 pounds (10 kg). Rilonacept injection is also used to treat recurrent pericarditis (swelling of the sac around the heart) and also to prevent the return of pericarditis in adults and children 12 years of age or older. Rilonacept is in a class of medications called interleukin antagonists. It works by blocking the activity of interleukin, a substance in the body that causes inflammation.

How should this medicine be used?

Rilonacept comes as a powder in a vial to be mixed with a liquid to inject subcutaneously (under the skin). To treat CAPS, FCAS, or MWS or to treat or prevent pericarditis in adults, it is usually given as two injections for the first dose, followed by one injection once a week. To treat CAPS, FCAS, or MWS or to treat or prevent pericarditis in children, the drug is usually given as one or two injections for the first dose, followed by one injection once a week. To treat DIRA, is usually given as one or two injections once a week. Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Use rilonacept injection exactly as directed. Do not use more or less of it or use it more often than prescribed by your doctor.

Your doctor or nurse will show you or a caregiver how to mix and inject a dose of rilonacept injection at home. Before you use rilonacept injection for the first time, you and the person who will be giving the injections should read the manufacturer's information for the patient that comes with it. These instructions describe how to mix and inject a dose of rilonacept. Be sure that you understand these directions. Ask your healthcare provider if you have any questions about when you should use the medication, where on your body you should inject the medication, how to give the injection, or what type of syringe and needle to use.

You should mix the medication right before you plan to inject it. However, you may mix the medication in advance, store it at room temperature, and use it within 3 hours.

Always look at rilonacept solution before injecting it. Check that the expiration date has not passed and that the liquid is clear and colorless to slightly yellow. The liquid should not contain visible particles. Do not use if it is expired or if the liquid is cloudy, discolored, or contains particles.

You may inject rilonacept in the front of the middle of your thighs or in your lower stomach except for the 2-inch (5-centimeter) area around the navel (belly button). If someone else is giving you the injection, it can be injected into the outer area of your upper arms. Use a different spot for each injection. Do not inject into an area where your skin is red, bruised, tender, or hard. Do not inject close to a vein you can see under the skin.

Do not reuse or share syringes or needles. Dispose of used vials, syringes, and needles in a puncture-resistant container that is out of the reach of children. Talk to your doctor or pharmacist about how to dispose of the puncture-resistant container.

Ask your pharmacist or doctor for a copy of the manufacturer's information for the patient.

Other uses for this medicine

This medication may be prescribed for other uses; ask your doctor or pharmacist for more information.

What special precautions should I follow?

Before using rilonacept injection,

  • tell your doctor and pharmacist if you are allergic to rilonacept, any other medications, or any of the ingredients in rilonacept injection. Ask your pharmacist for a list of the ingredients.
  • tell your doctor and pharmacist what other prescription and nonprescription medications, vitamins, nutritional supplements, and herbal products you are taking or plan to take. Be sure to mention any of the following: adalimumab (Humira); anakinra (Kineret); canakinumab (Ilaris); certolizumab (Cimzia); corticosteroids such as cortisone acetate, dexamethasone (Hemady), fludrocortisone, hydrocortisone (Alkindi Sprinkle, Cortef), and prednisone (Rayos); etanercept (Enbrel); golimumab (Simponi, Simponi Aria); infliximab (Avsola, Remicade); and warfarin (Jantoven). Your doctor may need to change the doses of your medications or monitor you carefully for side effects. Many other medications may also interact with rilonacept, so be sure to tell your doctor about all the medications you are taking, even those that do not appear on this list.
  • tell your doctor if you have or have ever had asthma, diabetes, high cholesterol or triglycerides, or conditions that affect your immune system.
  • tell your doctor if you are pregnant, plan to become pregnant, or are breast-feeding. If you become pregnant while using rilonacept injection, call your doctor.
  • you should know that rilonacept injection may decrease your ability to fight infection from bacteria, viruses, and fungi and increase the risk that you will get a serious infection. Tell your doctor if you often get any type of infection or if you have or think you may have any type of infection now. This includes minor infections (such as open cuts or sores), infections that come and go (such as herpes or cold sores), and chronic infections that do not go away. Also tell your doctor if you have or if you have ever had human immunodeficiency virus (HIV), hepatitis B virus infection (HBV; an ongoing liver infection) or hepatitis C virus infection (HCV; an ongoing liver infection). If you experience any of the following symptoms during or shortly after your treatment with rilonacept injection, call your doctor immediately: fever, sweats, or chills; sore throat; cough; warm, red, or painful skin or sores on your body; frequent, urgent, or painful urination; or other signs of infection.
  • you should know that using rilonacept injection increases the risk that you will develop tuberculosis (TB; a serious lung infection), especially if you are already infected with tuberculosis but do not have any symptoms of the disease. Tell your doctor if you have or have ever had TB, if you have lived in a country where TB is common, or if you have been around someone who has TB. Your doctor may perform a skin test to see if you have an inactive TB infection. If necessary, your doctor will give you medication to treat this infection before you start using rilonacept injection. If you have any of the following symptoms of TB, or if you develop any of these symptoms during your treatment, call your doctor immediately: cough, coughing up blood or mucus, weakness or tiredness, weight loss, loss of appetite, chills, fever, or night sweats.
  • do not have any vaccinations without talking to your doctor.

What special dietary instructions should I follow?

Unless your doctor tells you otherwise, continue your normal diet.

What should I do if I forget a dose?

Call your doctor if you forget to inject a dose of this medication. Your doctor will tell you when to inject the missed dose and when to inject your next scheduled dose. Do not inject a double dose to make up for a missed one.

What side effects can this medication cause?

Rilonacept may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:

  • injection site pain, bruising, bleeding, swelling, redness, warmth, or itching
  • nausea
  • diarrhea
  • upset stomach
  • stuffy nose
  • numbness
  • muscle and joint pain (in patients with pericarditis)

Some side effects can be serious. If you experience any of these symptoms or those listed in the SPECIAL PRECAUTIONS section, call your doctor immediately or get emergency medical treatment:

  • hives; rash; itching; difficulty breathing or swallowing; swelling of the eyes, face, mouth, lips, tongue or throat; hoarseness; lightheadedness; fainting; or chest pain

Rilonacept may increase the risk of developing certain types of cancer. Talk to your doctor about the risks of using this medication.

Rilonacept may cause other side effects. Call your doctor if you have any unusual problems while taking this medication.

If you experience a serious side effect, you or your doctor may send a report to the Food and Drug Administration's (FDA) MedWatch Adverse Event Reporting program online ( or by phone (1-800-332-1088).

What should I know about storage and disposal of this medication?

Keep this medication in the carton it came in, tightly closed, and out of reach of children. Store it in a refrigerator and protect from light. Medication that has been mixed may be stored at room temperature and used within 3 hours. Dispose of any medication that is outdated or no longer needed.

It is important to keep all medication out of sight and reach of children as many containers (such as weekly pill minders and those for eye drops, creams, patches, and inhalers) are not child-resistant and young children can open them easily. To protect young children from poisoning, always lock safety caps and immediately place the medication in a safe location – one that is up and away and out of their sight and reach.

Unneeded medications should be disposed of in special ways to ensure that pets, children, and other people cannot consume them. However, you should not flush this medication down the toilet. Instead, the best way to dispose of your medication is through a medicine take-back program. Talk to your pharmacist or contact your local garbage/recycling department to learn about take-back programs in your community. See the FDA's Safe Disposal of Medicines website ( for more information if you do not have access to a take-back program.

In case of emergency/overdose

In case of overdose, call the poison control helpline at 1-800-222-1222. Information is also available online at If the victim has collapsed, had a seizure, has trouble breathing, or can't be awakened, immediately call emergency services at 911.

What other information should I know?

Keep all appointments with your doctor and the laboratory. Your doctor may order certain lab tests to check your body's response to rilonacept.

Do not let anyone else take your medication. Ask your pharmacist any questions you have about refilling your prescription.

It is important for you to keep a written list of all of the prescription and nonprescription (over-the-counter) medicines you are taking, as well as any products such as vitamins, minerals, or other dietary supplements. You should bring this list with you each time you visit a doctor or if you are admitted to a hospital. It is also important information to carry with you in case of emergencies.

Brand names

  • Arcalyst®
Last Revised - 04/15/2022