Tacrolimus (tacrolimus)

Tacrolimus is a macrolide immunosuppressant produced by Streptomyces tsukubaensis.

Tacrolimus is a macrolide immunosuppressant produced by Streptomyces tsukubaensis. Tacrolimus is commercially available for topical use as a 0.03 or 0.1% ointment. The exact mechanism(s) of action of tacrolimus in the treatment of atopic dermatitis has not been elucidated but appears to involve inhibition of the activation of T cells.

Tacrolimus also has been shown to inhibit release of mediators from skin mast cells and basophils and to downregulate the expression of high-affinity receptors for immunoglobulin E (IgE) on Langerhans cells. Although tacrolimus is not genotoxic and does not interact directly with DNA, the drug may impair local immunosurveillance.

Following single or multiple applications of tacrolimus 0.3% ointment (not commercially available in the US) to atopic dermatitis lesions in adults or children 5-11 years of age, tacrolimus was not appreciably absorbed into systemic circulation (e.g., the apparent systemic bioavailability was less than 0.5%). Use of tacrolimus ointment on the face or neck, large areas of the body (i.e., >50% of the total body surface area), or areas of broken skin theoretically may increase systemic exposure to the drug. The lowest blood tacrolimus concentration at which systemic effects can be observed is as yet unknown.

Tacrolimus does not appear to accumulate systemically following intermittent topical application of the ointment for periods up to 1 year. Following systemic administration, tacrolimus is extensively metabolized in the liver and in the GI tract, principally via oxidation by cytochrome P-450 3A (CYP3A) isoenzymes.

USES: This form of tacrolimus is used on the skin to treat a skin condition called eczema (atopic dermatitis) in patients who have not responded well to (or should not use) other eczema medications. Eczema is an allergic-type condition that causes red, irritated, and itchy skin. This drug works by weakening the skin's defense (immune) system, thereby decreasing the allergic reaction and relieving the eczema.

Tacrolimus belongs to a class of drugs known as topical calcineurin inhibitors (TCIs). For children 2 to 15 years of age, the lower strength product should be used.

Generic name: tacrolimus
Pronunciation: (ta-KROE-li-mus)
Drug class: Macrolide Immunosuppressants - Topical
Therapeutic class: Dermatological

The following indications are listed for Tacrolimus:

• Atopic Dermatitis
• Intractable Eczema

Also known as: Atopic Eczema, Disseminated Neurodermatitis, Refractory Eczema.