Doxepin incorporated into a dermatologic cream: an assessment of both doxepin antipruritic action and doxepin action as an inhibitor of papules, in allergen and histamine-caused pruritus.

"Doxederm", a 5% doxepin hydrochloride ("doxepin") cream, has been used for assessments on patients' response to histamine and allergens by means of a prick test. Parameters selected papule diameters, and pruritus intensity. Doxederm was applied: (a) immediately before tests, (b) 10 minutes after tests, and (c) 72 hours before tests. All test reactions have been compared to similar tests that had been performed with a placebo cream. Tests yielded the following findings: (1) a remarkable remission of pruritus when doxederm was applied according to above mentioned (a), (b), and (c) schedules; (2) no inhibition of papule size --should either antigens or histamine be administered, could be observed when doxederm was applied immediately before tests or 10 minutes after tests had been performed (p > 0.10 vs placebo); (3) an evident remission of papules when doxederm had been applied 72 hours before tests were performed. No difference, however, could be detected with patientś forearms placebo cream had been applied whereon (difference among previously observed papules, and papules observed 72 after doxederm application: p > 0.005. Difference between doxederm and placebo: p > 0.10). Pursuant to the above mentioned observations, it can be suggested that doxederm evidences a highly siwft response on pruritus. Doxederm local effect, however, does not alter histaminic responses. Responses, however, are likely to be altered after a doxederm percutaneous absorption.