Relief of pruritus in patients with atopic dermatitis after treatment with topical doxepin cream. The Doxepin Study Group.

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.