ORIGINAL ARTICLESSilexan in generalized anxiety disorder investigation of the therapeutic dosage range in a pooled data setKasper, Siegfrieda; Möller, Hans-Jürgenb; Volz, Hans-Peterc; Schläfke, Sandrad; Dienel, Angelikad Author Information aDepartment of Psychiatry and Psychotherapy, Medical University of Vienna, Vienna, Austria bClinic for Psychiatry and Psychotherapy, Ludwig Maximilians University, Munich cHospital for Psychiatry, Psychotherapy and Psychosomatic Medicine, Schloss Werneck dDr. Willmar Schwabe GmbH & Co. KG, Karlsruhe, Germany Correspondence to Siegfried Kasper, MD, Department of Psychiatry and Psychotherapy, Medical University of Vienna, Währinger Gürtel 18-20, 1090 Vienna, Austria Tel: +43 140 400 35680; fax: +43 140 400 30990; e-mail: [email protected] Received December 1, 2016 Accepted March 13, 2017 International Clinical Psychopharmacology: July 2017 - Volume 32 - Issue 4 - p 195-204 doi: 10.1097/YIC.0000000000000176 Buy Metrics Abstract Silexan, a special active substance produced from Lavandula angustifolia, is efficacious in subsyndromal anxiety at a dose of 80 mg/day, but its effective dosage in generalized anxiety disorder (GAD) has yet to be defined. In two double-blind, placebo-controlled trials, daily doses of 10, 40, 80, and 160 mg silexan were administered for 10 weeks. A total of 925 adults with GAD according to Diagnostic and Statistical Manual of Mental Disorders (DSM) criteria and a Hamilton Anxiety Scale (HAMA) total score of at least 18 points were analyzed for efficacy. We assessed the change versus baseline for the HAMA and the Covi Anxiety Scale, the Clinical Global Impressions scale, the Sheehan Disability Scale, and the SF-36 health status questionnaire using analysis of variance and covariance. Silexan 160 mg/day was superior to placebo for all efficacy outcomes investigated, with responder rates exceeding 60% on the basis of HAMA and Clinical Global Impressions criteria. For the 80 mg/day dosage, superiority over placebo could be shown in one trial as well as in the pooled analysis. The risk of adverse events under silexan was similar to placebo for all dosages investigated. In GAD silexan 160 mg/day is efficacious whereas 80 mg/day may represent the lower end of the therapeutic range. Daily doses up to 160 mg were well tolerated. Copyright © 2017 Wolters Kluwer Health, Inc. All rights reserved.