Background: Atopic dermatitis is associated with severe pruritus for which effective topical treatment is lacking. As a potent H1 and H2 antagonist, the antipruritic effect of topical doxepin was first demonstrated in histamine-induced itch in nonatopic volunteers.
Objective: The current study was undertaken to compare the efficacy and safety of topical 5% doxepin cream in relieving pruritus associated with atopic dermatitis.
Methods: A total of 270 patients with atopic dermatitis who had daily moderate to severe pruritus for at least 1 week were enrolled in the double-blind, vehicle-controlled, multicenter study. Treatment was randomly assigned: 5% doxepin cream or vehicle cream was applied twice on the day of the baseline visit and four times daily for the remainder of the 7-day trial.
Results: Relief of pruritus was achieved in 85% of doxepin-treated patients and 57% of vehicle-treated patients by day 7; a majority of these positive responses occurred during the first 24 hours. Pruritus severity scores demonstrated significantly greater improvement with topical doxepin at each study visit (p < 0.01). Visual analogue scales for pruritus severity and pruritus relief showed similar improvement in the doxepin-treated group. At each of three visits, the physician's global evaluation for relief of pruritus also showed significant improvement in the doxepin treatment group (p < 0.01). The physician's global evaluations of eczema significantly favored topical doxepin on day 7 (p < 0.01). Nineteen patients withdrew from the study because of adverse effects (doxepin, n = 16; vehicle, n = 3). The most commonly reported were localized stinging or burning (doxepin group, n = 39; vehicle group, n = 34) and drowsiness (doxepin group, n = 37; vehicle group, n = 3), all of which decreased in frequency and severity over time.
Conclusion: Topical doxepin is effective in reducing pruritus in patients with atopic dermatitis. It has an apparent short-term low risk of major side effects or sensitization.