Montelukast is efffective in Atopic Dermatitis ?

Montelukast treatment of moderate to severe atopic dermatitis in adults: a randomized, double-blind, placebo-controlled trial

Journal of Drugs in Dermatology , Sept-Oct, 2005

The authors present a two-center, randomized, double-blind, placebo-controlled trial to evaluate the efficacy of montelukast in the treatment of moderate to severe atopic dermatitis. Fifty-nine patients were recruited for the study and randomly assigned to 1 of 2 treatment arms: 10 mg of montelukast once daily or placebo for 4 weeks. No statistically significant differences in disease activity were noted in the 2 groups at baseline. Patients were required to undergo a wash-out period of 2 weeks and no systemic or topical treatment, with the exception of emollients, was allowed during the study. The primary outcome was the modified eczema area and severity index (EASI) score. This score is the sum of a score for pruritus and the EASI score. A secondary outcome was the pruritus score alone. Patients were assessed at baseline, after the wash-out period, and at weeks 1, 2, and 4 of treatment. Six patients dropped out of the study before beginning treatment. Drop-out occurred in 6 patients during the study secondary to either worsening of their atopic dermatitis or not returning for follow-up visits. As the intention-to-treat analysis was used, these latter 6 patients were included in the analysis giving a total of 53 patients. No statistically significant difference was noted between the montelukast and placebo groups. No adverse events were reported.
Comment
The authors present a well-designed study to evaluate the efficacy of montelukast in the treatment of moderate to severe atopic dermatitis. Rationale for the use of montelukast in atopic dermatitis is based on anecdotal reports as well as prior studies. As leukotrienes are important in the pathogenesis of atopic disorders such as asthma and allergic rhinitis, it is possible they also play a role in atopic dermatitis. Synthesis of leukotrienes, determined by urinary excretion of leukotriene E4, was studied in 8 patients with atopic dermatitis compared with 8 healthy controls. (1) Patients with atopic dermatitis were found to have a statistically significant increase (4.5-fold) in leukotriene E4 excretion in comparison to controls. Hence it is theoretically possible that a leukotriene antagonist such as montelukast would improve atopic dermatitis. This study fails to demonstrate such efficacy. One reason may be that the investigators considered a 60% reduction in scoring as significant. Prior studies have shown efficacy. (2,3) These studies involved fewer patients and considered smaller reductions as significant. For example in Yanase et al, a 30% reduction in scoring was considered significant. This study confirms that the efficacy of montelukast in the treatment of atopic dermatitis is in no way dramatic. It may improve atopic dermatitis modestly at best and is certainly not suitable as a monotherapy. However, it may be useful in combination with a topical or systemic agent in a subset of patients.
References
1. Fauler J, et al. Enhanced synthesis of cysteinyl leukotrienes in atopic dermatitis. British Journal of Dermatology. 1993;128(6):627-630.
2. Eustachio N, et al. Efficacy and tolerability of montelukast as a therapeutic agent for severe atopic dermatitis in adults. Acta Derm Venereol. 2002; 82:297-320.
3. Yanase DJ, et al. The leukotriene antagonist montelukast as a therapeutic agent for atopic dermatitis. Journal of the American Academy of Dermatology. 2001; 44(1):89-93.
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