FK 506 is a type of:
Tacrolimus (FK506)- structurally a macrolide antibiotic which is a newer immunosuppressant chemically different from cyclosporine, but having the same mechanism of action, and is -100 times more potent. It binds to a different cytoplasmic immunophilin protein labeled 'FKBP', but the subsequent steps are the same, i.e. inhibition of helper T cells calcineurin. Tacrolimus is administered orally as well as by i.v. infusion. Oral absorption is variable and decreased by food. It is metabolized by CYP3A4 Section 14 and excreted in bile with a longer tlh of 12 hour. Therapeutic application, clinical efficacy as well as toxicity profile are similar to cyclosporine. It is paicularly valuable in liver transplantation because its absorption is not dependent on bile. Because of more potent action, itis also suitable for suppressing acute rejection that has set in. Hypeension, hirsutism and gum hyperplasia are less marked than cyclosporine, but tacrolimus is more likely to precipitate diabetes, cause neurotoxicity, alopecia, and diarrhea. Dose-limiting toxicity is renal. ESSENTIALS of MEDICAL PHARMACOLOGY SIXTH EDITION -K. D TRIPATHI Page:853 T
Immunoglobulin antibody
Non-depolarizing muscle relaxant
Macrolide antibiotic
Opioid anaesthetic
Immunomodulators