Topical tacrolimus : efficacy and tolerability

Tacrolimus, formulated as a 0.1% or 0.03% ointment, is the first topical immunosuppressant to receive widespread regulatory approval. Currently, it is only approved for the second-line treatment of moderate or severe atopic eczema in adults and children >2 years of age. Intent-to-treat response rates in eczema after 12 weeks of topical tacrolimus range from 27.5% to 40.7%, significantly higher than placebo (p<0.001). Open-label data for up to 4 years' follow-up supports ongoing efficacy and safety. Potency of the 0.1% formulation is at least equivalent to that of mid-potency topical corticosteroids, and greater than 1% pimecrolimus cream. It is well-tolerated and systemic absorption is minimal. Main adverse events are sensations of skin burning and pruritis, both of which are usually mild and self-limiting. Unlike topical corticosteroids, there is no potential for skin atrophy. Risk of malignancy with topical tacrolimus is an area of ongoing controversy. While the currently available evidence does not support an increased risk of malignancy, the possibility is not excluded. There is a lack of data specifically in patients who have failed conventional therapies, which may undermine its place in treatment guidelines as a second-line agent, and this indication requires clarification. There is presently insufficient evidence to support the routine use oftacrolimus ointment in conditions other than atopic eczema, although case reports are supportive of further study.