RT Book, Section A1 Bauer, Larry A. A2 Bauer, Larry A. SR Print(0) ID 3518052 T1 Chapter 16. Tacrolimus T2 Applied Clinical Pharmacokinetics, 2e YR 2008 FD 2008 PB The McGraw-Hill Companies PP New York, NY SN 978-0-07-147628-7 LK accesspharmacy.mhmedical.com/content.aspx?aid=3518052 RD 2024/03/29 AB Tacrolimus (also known as FK506) is a macrolide compound with immunosuppressant actions that is used for the prevention of graft rejection in solid organ transplant patients.1,2 Currently, it is approved for use in heart, liver, and renal transplant patients.1 It is also used in heart-lung and other solid organ transplant recipients, as well as the treatment of graft-versus-host disease in hematopoietic stem cell transplant patients.1,2 The immunomodulating effects of tacrolimus result from its ability to block the production of intraleukin-2 and other cytokines produced by T-lymphocytes.3 Tacrolimus binds to FK-binding protein (FKPB), an intracellular cytoplasmic protein found in T-cells. The tacrolimus-FKPB complex interacts with calcineurin, inhibits the catalytic activity of calcineurin, and blocks the production of intermediaries involved with the expression of genes regulating the production of cytokines.