The safety of tacrolimus ointment for the treatment of atopic dermatitis: a review

Tacrolimus ointment is a topical calcineurin inhibitor (TCI) that was developed specifically for the treatment of atopic dermatitis (AD). It is one of the most extensively tested dermatological products, with more than 19 000 patients (including approximately 7600 children) having participated in the tacrolimus ointment clinical development programme. Recent regulatory reviews have focused on the potential risk of malignancy with TCIs, based on their mode of action and the effects of systemic tacrolimus when given to transplant recipients. Studies have shown, however, that the systemic absorption of tacrolimus when applied topically is very low, with blood concentrations being below the level of quantification in most patients. Moreover, TCIs are not associated with a decrease in immunocompetence in the skin and there is no increase in the incidence of infections with long-term treatment. More than 5.4 million prescriptions for tacrolimus ointment have been issued worldwide, with no evidence of an increased risk of malignancy in adults or children compared with the general population. Similarly, epidemiological studies have failed to demonstrate an increased incidence of skin cancer in patients using TCIs. The most common adverse events (AEs) that occur with tacrolimus ointment treatment are transient application-site reactions, such as burning or pruritus. These complications are related to disease severity, and decrease in frequency over time as AD improves. The incidence of nonapplication-site AEs does not increase with long-term treatment, and most such events occurring in clinical trials were considered to be unrelated to therapy. Although it is important that clinicians are aware of the recent changes in product labelling, extensive clinical trials continue to show that tacrolimus ointment is well tolerated, and is generally an effective therapy for suitable patients with AD.