Rilonacept (Araclyst) is now approved to treat recurrent pericarditis and to reduce the risk of recurrence in adults and children 12 years of age and older. It is given as a weekly subcutaneous injection. The drug was previously approved to treat cryopyrin-associated periodic syndromes, including familial cold autoinflammatory syndrome, and Muckle-Wells syndrome in adults and children ages 12 years and older and to maintain remission of deficiency of interleukin-1 (IL-1) receptor antagonist in adults and pediatric patients weighing 10 kg or more.

Rilonacept is an IL-1[alpha] and IL-1[beta] cytokine trap. It acts as a decoy receptor that attracts both IL-1[alpha] and IL-1[beta], preventing them from interacting with the real receptors. IL-1 is an important cytokine with many inflammatory effects and has been implicated as a causative factor in pericarditis.

The efficacy and safety of rilonacept in treating pericarditis was evaluated in a double-blind, placebo-controlled, randomized withdrawal, multinational phase 3 study. Eighty-six patients were enrolled and received rilonacept for 12 weeks, after which half the patients received placebo and half continued on rilonacept. Rilonacept reduced the risk of recurrence of pericarditis by 96%. Two patients who received rilonacept had a relapse, but the relapse occurred during a temporary interruption in the drug regimen. Those in the placebo group who had a recurrence of pericarditis received bailout rilonacept, which resolved the pericarditis.

The most common adverse effects from rilonacept are injection-site reactions and upper respiratory tract infections. Rilonacept can also cause serious, life-threatening infections and hypersensitivity reactions. Patients should avoid live vaccines while receiving rilonacept.

Nurses should teach patients to avoid injecting the drug into an area that is already swollen or red, and to be aware of signs and symptoms of infection. The prescriber should be notified immediately if a patient develops an infection. Nurses should assess the patient's vaccination history and administer any recommended vaccinations prior to starting rilonacept.

Nurses should also educate patients and caregivers on the proper aseptic reconstitution of rilonacept and subcutaneous administration technique. A sterile syringe and needle are used to reconstitute the drug with preservative-free sterile water, and a new sterile syringe and needle are used for administration. The drug should be injected subcutaneously into any site, including the arm, abdomen, and thigh on a rotating basis.

For complete prescribing information for rilonacept and specific information related to reconstitution and administration, go to http://www.accessdata.fda.gov/drugsatfda_docs/label/2021/125249s049lbl.pdf.