Understanding ARCALYST (rilonacept)
ARCALYST® is a prescription medication that blocks interleukin-1 (IL-1) signaling, which is involved in inflammation. It is approved for treating Recurrent Pericarditis (RP), Cryopyrin-Associated Periodic Syndromes (CAPS) in patients aged 12 and older, and Deficiency of Interleukin-1 Receptor Antagonist (DIRA). ARCALYST is typically given as a weekly subcutaneous injection after an initial loading dose, with the first dose usually administered by a healthcare professional.
Approved Injection Sites: Where Do You Inject ARCALYST?
ARCALYST is injected into the fatty tissue under the skin. The recommended areas are the abdomen (avoiding the 2-inch area around the navel), the front of the middle thighs, and the outer area of the upper arms. The abdomen is often preferred for its absorption speed, while the upper arm may require assistance for self-injection. Avoid injecting into bruised, red, tender, or hard skin, as well as muscles, veins, scars, or near visible veins.
The Importance of Rotating Injection Sites
Rotating injection sites each week is important. Using the same spot repeatedly can lead to lipodystrophy (lumps or extra fat deposits), reduced medication absorption, and increased discomfort. If a dose requires two injections, they must be given at two different sites on the same day. Tracking injection locations can help ensure sites have time to recover.
Comparison of ARCALYST Injection Sites
| Site | Absorption Speed | Ease of Self-Injection | Key Considerations |
|---|---|---|---|
| Abdomen | Fastest | High | Avoid the 2-inch area around the navel. |
| Thigh | Slower than abdomen | High | Inject into the front, middle of the thigh. |
| Upper Arm | Moderate speed | Low to Medium | May require assistance for self-administration. |
Preparing and Administering the Injection
ARCALYST powder must be mixed with sterile water before use. Healthcare providers typically provide training on mixing and injection techniques. The process involves reconstituting the powder, drawing the correct dose into a syringe, injecting the medication into a pinched fold of skin at a clean site (which can take up to 30 seconds), and safely disposing of used supplies in a sharps container. Always follow the provided 'Instructions for Use' and consult your healthcare provider with questions.
Potential Side Effects and Precautions
Common side effects include injection-site reactions and upper respiratory infections. ARCALYST affects the immune system, increasing infection risk. It should not be used with TNF inhibitors or other IL-1 blockers and is not recommended for patients with active infections. Live vaccines should be avoided during treatment.
Conclusion
Effective ARCALYST therapy depends on proper administration. The approved subcutaneous injection sites are the abdomen, thigh, and upper arm. Regular rotation of these sites each week is critical to avoid skin complications and ensure consistent drug absorption. For any questions about injection sites or the procedure, consult your healthcare provider or the manufacturer's resources.
For more detailed patient instructions, you can visit the official manufacturer's website: ARCALYST® (rilonacept) How to Use Guide
