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Medications and Drugs

Brand Names: Arcalyst

Generic Name: rilonacept (Pronunciation: ril ON a sept)

What is rilonacept (Arcalyst)?

Rilonacept is used to treat some of the symptoms of rare genetic conditions such as Familial Cold Auto-inflammatory Syndrome (FCAS) or Muckle-Wells Syndrome (MWS).

FCAS and MWS are inflammatory disorders in which the body develops certain symptoms without a known cause (such as virus, bacteria, or illness). These symptoms include fever, chills, fatigue, and joint pain. More serious symptoms may involve the bones and joints, the central nervous system (deafness, vision loss, mental impairment), or major organs such as the kidneys.

Rilonacept may treat or prevent the symptoms of Familial Cold Auto-inflammatory Syndrome (FCAS) or Muckle-Wells Syndrome (MWS). However, this medication is not a cure for these inherited conditions.

Rilonacept may also be used for other purposes not listed in this medication guide.

What are the possible side effects of rilonacept (Arcalyst)?

Get emergency medical help if you have any of these signs of an allergic reaction: hives; difficulty breathing; swelling of your face, lips, tongue, or throat.

Stop using rilonacept and call your doctor at once if you have a serious side effect such as:

  • new signs of infection such as fever, chills, sore throat, flu symptoms, easy bruising or bleeding, or unusual weakness;
  • black, bloody, or tarry stools;
  • coughing up blood or vomit that looks like coffee grounds;
  • fever and chills with headache, neck stiffness, increased sensitivity to light, purple spots on the skin, and/or seizure (convulsions); or
  • pain or burning when you urinate.

Less serious side effects may include:

  • sneezing, runny or stuffy nose, sore throat, cough;
  • nausea, stomach pain, diarrhea; or
  • pain, swelling, redness, itching, bleeding, or other irritation where the medicine was injected;

This is not a complete list of side effects and others may occur. Tell your doctor about any unusual or bothersome side effect. You may report side effects to FDA at 1-800-FDA-1088.

What is the most important information I should know about rilonacept (Arcalyst)?

You should not use this medication if you are allergic to rilonacept, or if you have any type of infection. Before using rilonacept, tell your doctor if you have a history of tuberculosis.

Do not receive a "live" vaccine while you are being treated with rilonacept. The live vaccine may not work as well during this time, and may not fully protect you from disease. Avoid coming into contact with anyone who has recently received a live vaccine. There is a chance that the virus could be passed on to you. Make sure you are current on all vaccines before you start treatment with rilonacept.

To be sure this medication is not causing harmful effects, your blood may need to be tested on a regular basis. Do not miss any follow-up visits to your doctor for blood or urine tests.

Contact your doctor at once if you develop signs of infection such as fever, chills, sore throat, flu symptoms, easy bruising or bleeding (nosebleeds, bleeding gums), loss of appetite, nausea and vomiting, mouth sores, or unusual weakness.

Do not use this medication more often than once per week unless your doctor has told you to.

Report Problems to the Food and Drug Administration

You are encouraged to report negative side effects of prescription drugs to the FDA. Visit the FDA MedWatch website or call 1-800-FDA-1088.

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