To print: Select File and then Print from your browser's menu --------------------------------------------------------------------------------------- Title: Washout Periods Similar for Desloratadine and Levocetirizine, Allowing for Skin Prick Tests: Presented at AAAAI URL: http://www.pslgroup.com/dg/21E936.htm Doctor's Guide March 20, 2008
By Ed Susman PHILADELPHIA -- March 20, 2008 -- Patients who are taking the histamine H1-receptor antagonist desloratadine appear to wash out the effects of the drug in the same amount of time as those taking levocetirizine, so allergists can conduct skin prick tests on patients taking desloratadine without having to delay the tests due to the drug's longer half-life. "We conducted these studies because there is considerable clinical significance to how long it takes drugs to wash out of the system and allow testing with skin prick methods," explained investigator Kamal Mesbah, PharmD, Medical Advisor, Schering-Plough, Levallois-Perret, France. Dr. Mesbah noted that desloratadine has a half-life of 27 hours compared with the 7-hour half-life of levocetirizine, but in his poster presentation on March 17 here at the American Academy of Allergy, Asthma & Immunology (AAAAI) Annual Meeting, he demonstrated that the time to the end of the effect of the 2 drugs was basically similar. Doctors can therefore tell their patients to stop taking their medication and come back for skin testing after 1 week. "It doesn't matter if the patient is taking desloratadine or levocetirizine," he said. In their study, Dr. Mesbah and colleagues found that the inhibitory effects of desloratadine on histamine- and allergen-induced skin responses disappeared 5 days after the last dose of desloratadine and 4 days after the last dose of levocetirizine. "This finding is of direct clinical relevance to allergists and dermatologists to permit accurate allergen skin testing in patients receiving desloratadine and levocetirizine," he noted. The researchers enrolled 36 subjects to receive a 7-day course of desloratadine, levocetirizine, or placebo. Each group had 12 subjects. They returned for 12 clinic visits over 19 days to determine when the wheal-and-flare response would be seen after drug discontinuation. There was no significant difference in time to drug washout between the 2 active treatments, Dr. Mesbah said, and there did not appear to be a difference between the 2 drugs in their effectiveness in preventing the skin reactions. Funding for this study was provided by Schering-Plough. [Presentation title: Duration of Inhibition- and Allergen-Induced Wheal-and-Flare Responses After Discontinuation of Desloratadine or Levocetirizine. Abstract 776] --------------------------------------------------------------------------------------------- Copyright © 1999 P\S\L Consulting Group Inc. All rights reserved. Republication or redistribution of P\S\L content is expressly prohibited without the prior written consent of P\S\L. P\S\L shall not be liable for any errors, omissions or delays in this content or any other content on its sites, newsletters or other publications, nor for any decisions or actions taken in reliance on such content. --------------------------------------------------------------------------------------------- This news story was printed from *Doctor's Guide to the Internet* located at http://www.docguide.com --------------------------------------------------------------------------------------- Return to News Story Page This site is maintained by webmaster@pslgroup.com Please contact us with any comments, problems or bugs. All contents Copyright (c) 1998 P\S\L Consulting Group Inc. All rights reserved.