Orthoclone OKT3 is a medicine prescribed to treat organ rejection after a kidney, liver, or heart transplant. It comes in the form of an intravenous injection that is administered for 10 to 14 days. It works by making the immune system less active, so it stops attacking the newly transplanted organ. Common side effects include headaches, nausea, and diarrhea.
What Is Orthoclone OKT3?Orthoclone OKT®3 (muromonab-CD3) is a prescription medication approved to treat transplant rejection in people who have received a kidney, liver, or heart transplant. It is considered an immunosuppressant because it decreases the activity of the immune system. Orthoclone OKT3 is sometimes simply referred to as OKT3.
How Does Orthoclone OKT3 Work?Transplant rejection occurs when the immune system recognizes a transplanted organ as foreign and attacks it. T-lymphocytes (a type of white blood cell, sometimes simply called T-cells) play a major role in transplant rejection.
Orthoclone OKT3 is a laboratory-made antibody (a protein normally produced by the immune system) that recognizes and attaches to a specific protein found on T-cells (known as the cell differentiation cluster 3, or CD3). When Orthoclone OKT3 binds to CD3, it blocks the ability of T-cells to function properly. Because the T-cells cannot function properly, they are unable to attack the transplanted organ, and transplant rejection is stopped.