Herbal anxiolytic kava

Mischoulon, D. (2002). The herbal anxiolytics kava and valerian for anxiety and insomnia. Psychiatric Annals, 32, 55-60. 

Tlydroxyzine and kava kava are two alternatives. Patients with GAD demonstrated contmned efficacy for 3 months with hydroxyzine or bromazepam (not marketed in the United States), but not with placebo. Efficacy was maintained in 86% of the hydroxyzine group and 88% of the bromazepam group. A meta-analysis of randomized trials comparing the herbal preparation kava kava found it was more effective than placebo for anxiety during trial durations of 1 to 24 weeks. Many patients experienced CNS effects (e.g., tremors, drowsiness, restlessness, and headaches) and abdominal discomfort during short-term treatment. Because of recent reports of hepato-toxicity, kava kava is not recommended as an anxiolytic. ... 

There has been a relatively small number of clinical trials with kava, a majority of them conducted in Germany. Although kava is a herbal anxiolytic drink that is prepared in the South Seas as a water extract, most of the trials have been performed on commercially produced preparations that contain kavalactones extracted using organic solvents, such as ethanol and acetone. The kavalactone content of these formulations usually is between 30 and 70%. In addition, a number of studies have used individual synthetic preparations [e.g., (+)-kavainl rather than kava extracts which contain a mixture of at least six major active kavalactones. Thus, comparisons across studies in terms of clinical efficacy and adverse side-effects should not be made across studies unless they have used similar, standardized kava preparations. 

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