Tai Chi as an Intervention on Health Promotion for Older Adults: A Systematic Review

Abstract

Purpose: In June 2002 the authorization of medicinal drugs with kava extracts (Piper methysticum), which was used for the treatment of stress-related anxiety disorders, was withdrawn by the German Institute of Drugs and Medicinal Products (BfArM) because of an unfavorable risk-benefit ratio. The decision, which initially was based on several case reports on liver toxicity in 1999 and 2000, found a worldwide resonance. Methods: Literature on efficacy and safety of kava extracts was searched and related to the still ongoing legal dispute. Results: Between 1990 and 2000 several randomized controlled clinical studies have been published, which were the basis for the authorization of kava products in Germany for stress-related anxiety disorders in the past. However, in the course of time since 2002, the BfArM did not any longer accept these studies as proof of efficacy because of several deficits in the study protocols. In 2002, no study was left. The case reports were re-analyzed by a specialized hepatologist, who found that the risk of hepatotoxicitywas “rare” or “very rare” at its best and could not identify a specific pattern. However, the resulting publication was ignored completely by the BfArM. In fact, BfArMnowconsidered kava extracts being a ,,newentity“, because of their alleged unproven efficacy. That means that based on the most recent ICH-guidelines now the complete spectrum of preclinical studies has to be performed before undertaking a clinical trial. However, the administrative court of Cologne, Germany, underlined in its decision from 10. June 2014, that current rules of the proof of efficacy of a drug should not be applied retrospectively. Conclusion:Thedecision is importantnot only for kava, but for all drugs on the German market, e.g. for benzodiazepines, which were tested in the 1960s for efficacy. By the way, BfArM applied for revision. Contact: Karin Kraft, karin.kraft@med.uni-rostock.de