Tacrolimus

Tacrolimus is a "macrolide isolated from the culture broth of a strain of Streptomyces tsukubaensis that has strong immunosuppressive activity in vivo and prevents the activation of T-lymphocytes in response to antigenic or mitogenic stimulation in vitro." It is a calcineurin inhibitor. Originally used as an antirejection drug in organ transplantation, it has been found useful in other medicial applications.

Approved indications include therapy for Crohn's disease, and, in drug-eluting stents, as a means of preventing reocclusion after blood vessel revascularization. In topical form, it has been approved for atopic dermatitis.

Tacrolimus, and the related pimecrolimus, have also been employed for a number of off-label uses:

• Cutaneous lupus erythematosus
• Netherton syndrome
• Psoriasis
• Lichen sclerosus
• perioral dermatitis
• the skin lesions of dermatomyositis, vitiligo, steroid-induced rosacea, alopecia areata; and seborrheic dermatitis.