“Efficacy of Silexan in Sub-Threshold Anxiety: Meta-Analysis of Randomised, Placebo-Controlled Trials”, 2017-11-17 ():
[note: Kasper-authored] Sub-threshold psychiatric disorders do not fully meet the diagnostic criteria of syndromal disorders but may be associated with comparable disability. To investigate the anxiolytic effect of Silexan, an active substance from lavender oil for oral administration, in patients with sub-threshold anxiety, a meta-analysis that included all published trials with Silexan in this indication was performed.
3 randomized, placebo-controlled trials in sub-threshold anxiety disorders (anxiety disorder not otherwise specified, restlessness and agitation, mixed anxiety and depressive disorder) were included [ et al 2010, et al 2015, et al 2016]. Eligible participants with a baseline Hamilton Anxiety Rating Scale (HAMA) total score ≥ 18 points received 1 × 80 mg/day Silexan or placebo for 10 weeks. Outcomes included the HAMA, the Pittsburgh Sleep Quality Index, the Zung Self-rating Anxiety Scale, the Clinical Global Impressions questionnaire and the SF-36 health status inventory. Data were analysed using meta-analysis based on pooled raw data of individual patients (random effects models). A total of 697 patients were assessed for efficacy.
Silexan was superior to placebo in reducing the HAMA total score during 10 weeks’ treatment [mean value difference, 95% confidence interval: 3.83 (1.28; 6.37) points]. Superiority was comparably pronounced for psychic and somatic anxiety as well as for observer & self-rated anxiety. Silexan had a beneficial effect on sleep (secondary to the anxiolytic effect) without causing sedation and improved the patients’ health-related quality of life.
Adverse event incidence in both treatment groups was comparable [risk ratio: 1.06 (0.85; 1.33)].
Silexan has a statistically-significant and clinically meaningful anxiolytic effect in sub-threshold anxiety. The results cannot be generalized to other lavender oil products.
Acknowledgments: The research presented in this paper was funded by Dr. Willmar Schwabe GmbH & Co. KG, manufacturer of Silexan, who was also the sponsor of the trials included in the meta-analysis. The statistical analysis plan for the meta-analysis was conceived and the analyses were performed by the biostatistical department of Dr. Willmar Schwabe GmbH & Co. KG under the responsibility of co-author SS. The company also provided the raw data of the trials included into the analyses. A first draft of the manuscript was prepared by Andreas Völp, Ph.D., an independent medical writer who was reimbursed by Dr. Willmar Schwabe GmbH & Co. KG, who also independently performed the risk of bias assessments. Open access funding provided by Medical University of Vienna.
…Conflict of interest: Hans-Jürgen Möller has received grant/research support, consulting fees and honoraria within the last years from AstraZeneca, Bristol-Myers Squibb, Eli Lilly, GlaxoSmithKline, Janssen Cilag, Lundbeck, MSD, Novartis, Organon, Otsuka, Pfizer, Schwabe, Sepracor, Servier, and Wyeth. Hans-Peter Volz has served as a consultant or on advisory boards for Astra/Zeneca, Eli Lilly, Lundbeck, Pfizer, Schwabe, Janssen, Otsuka, Merz, Wyeth, neuraxpharm and has served on speakers’ bureaus for Astra/Zeneca, Eli Lilly, Lundbeck, Schwabe, Janssen, Merz, Wyeth, Lichtwer, Steigerwald, Hormosan, neuraxpharm and Bristol-Myers Squibb. Angelika Dienel and Sandra Schläfke are employees of Dr. Willmar Schwabe GmbH & Co. KG, manufacturer of Silexan. Siegfried Kasper received grants/research support, consulting fees and/or honoraria within the last 3 years from Angelini, AOP Orphan Pharmaceuticals AG, AstraZeneca, Eli Lilly, Janssen, KRKA-Pharma, Lundbeck, Neuraxpharm, Pfizer, Pierre Fabre, Schwabe and Servier.