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Fexofenadine, loratadine supported for reactions, but not chlorpheniramine.

Clinical Trials Week January 27, 2003 2003 JAN 27 – (NewsRx.com & NewsRx.net) — “The extent of the distribution of H-1-antihistamines into the skin and H-1-antihistamine activity in the skin are clinically relevant in the treatment of allergic skin disorders,” researchers in Canada report.

“In a prospective, randomized, double blind, parallel group, multiple dose study, we gave fexofenadine 180 mg, loratadine 10 mg, or chlorpheniramine 8 mg to 21 men (7 in each group). Before dosing and at 1, 3, 6, 9, and 24 hours after the first antihistamine dose as well as at 168, 192, and 216 hours after the first dose (12, 36, and 60 hours after the seventh and last consecutive daily H-1-antihistamine dose), we measured fexofenadine, loratadine, or chlorpheniramine concentrations in plasma and in skin tissue samples obtained through use of punch biopsies, along with suppression of histamine induced skin wheals and flares. in our site loratadine side effects

“Loratadine metabolites, including desloratadine and its metabolites, were not measured, and chlorpheniramine metabolites were not measured,” wrote F.E.R. Simons and colleagues, Winnipeg.

The researchers found that “all 21 participants completed the study. Skin/plasma fexofenadine ratios ranged from 1.2[+ or -]0.5 at 1 hour to 110[+ or -]74 at 24 hours, and skin fexofenadine concentrations exceeded loratadine and chlorpheniramine skin concentrations at each test time. This was reflected in significant wheal and flare suppression by fexofenadine in comparison with loratadine at 3 hours and in comparison with chlorpheniramine at 6 hours and 9 hours (wheal), and from 3-24 hours and at 192 hours (flare).

“Compared with fexofenadine, loratadine significantly suppressed the wheal at 192 hours, and compared with chlorpheniramine, it significantly suppressed the wheal at 9 hours and the flare at 24 and 192 hours. At no time did chlorpheniramine suppress the wheal or flare significantly more than fexofenadine or loratadine.” The researchers concluded: “In skin disorders for which H-1-antihistamines are recommended, these results support the use of fexofenadine or loratadine, and they indicate the need for reexamination of the use of chlorpheniramine.” Simons and colleagues published their study in Journal of Allergy and Clinical Immunology (Clinical pharmacology of H-1-antihistamines in the skin. J Allergy Clin Immunol, 2002;110(5):777-783). website loratadine side effects

The contact person for this report is F.E.R. Simons, 820 Sherbrook St., Winnipeg, MB R3A 1R9, Canada.

To subscribe to the Journal of Allergy and Clinical Immunology, contact the publisher: Mosby, Inc., 11830 Westline Industrial Dr., St. Louis, MO 63146-3318 USA.

The information in this article comes under the major subject areas of Allergy Medicine, Dermatology and Pharmacology.

This article was prepared by Clinical Trials Week editors from staff and other reports.