商品名：Protopic, FK506
Tacrolimus is a microbial product isolated from the organism Streptomyces tsukubaensis. Tacrolimus binds to an intracellular receptor and subsequently binds to calcineurin and inhibits the calcineurin pathway that stimulates the nuclear factor, NFAT. The action resembles that of cyclosporine (both drugs are calcineurin inhibitors), although the cellular receptors differ. By inhibiting the action of NFAT, tacrolimus decreases synthesis of inflammatory cytokines. In particular, synthesis of IL-2 is inhibited, which results in decreased activation of T lymphocytes. It is 10-100 times more potent than cyclosporine. Tacrolimus inhibits release of mast cell and basophil mediators and decreases inflammatory mediator expression.
Tacrolimus is used as an immunosuppressive drug to treat autoimmune disease, prevent organ transplant rejection, and treat atopic dermatitis. Most use in animals is with a topical formulation. It has been applied topically (ointment) for localized areas of atopic dermatitis. In some cases after resolution of lesions with systemic treatment with cyclosporine, isolated skin lesions are managed topically with tacrolimus ointment. There has been limited use for preventing renal transplant rejection in cats because the pharmacokinetics have been highly variable. A related drug, pimecrolimus, also has been used topically.
劑量數字暫停提供：VetPro 的劑量改依 DRUGAPI 藥物資料庫對外的內容，DRUGAPI 目前不提供可直接計算的劑量。下方列出 DRUGAPI 的審查結論與劑量審查引用的來源；計算機可手動輸入劑量換算。
公開證據可支持人用皮膚與移植產品的精確警戒、犬眼科調製清單的狹窄法規脈絡，以及個別犬貓研究；不能建立通用動物用物種、途徑、適應症、配方、劑量、不良反應頻率或自動交互作用。
依出現頻率分組；嚴重副作用獨立列出，臨床上需立即辨識。