Sirolimus (Rapamycin) analysis in blood using High-Performance Liquid Chromatography (HPLC) is a test designed to accurately measure sirolimus levels in the body. Sirolimus is an immunosuppressive drug commonly administered to patients who have undergone organ transplantation, as it helps prevent organ rejection. The test requires collecting a blood sample, which is then analyzed using advanced HPLC techniques to precisely determine the drug concentration. Monitoring sirolimus levels is essential to ensure the effectiveness of therapy and to avoid potential side effects such as toxicity or insufficient dosage. The results of this analysis assist physicians in adjusting dosages according to individual patient needs, thereby improving treatment outcomes and ensuring patient safety. This test is considered an essential part of the care of patients receiving immunosuppressive therapy.