Piper methysticum (kava kava) is a plant native to the Pacific Island region, and has been used ceremonial for thousands of years. The active ingredients are a group of substances know as kava lactones (AKA kava pyrones). Four lactones in kava have been found to have significant analgesic and anesthetic effects via non-opiate pathways. Kava's most popular application is as a natural anxiolytic, comparing favorably in several studies to a number prescription medications, including benzodiazepines. CNS effects seem to be mediated by several mechanisms. Studies have been conflicting regarding its GABA-receptor-binding capacity, although this has been found to occur in some studies. In vitro kava has been found to block norepinephrine uptake. It also has some anti-convulsant capabilities, which appear to be mediated by Na+ channel receptor sites. The therapeutic dosage is in the range of 50-70 mg kava lactones three times daily. The most common side effect, usually seen only with long-term, heavy usage of the herb, is a scaly skin rash called "kava dermopathy." It has also been know to potentiate other medications such as barbiturates and Xanax.
卡瓦胡椒（卡瓦）是一种原产于太平洋岛屿地区的植物，数千年来一直被用于仪式场合。其活性成分是一组被称为卡瓦内酯（又称卡瓦吡喃酮）的物质。已发现卡瓦中的四种内酯通过非阿片类途径具有显著的镇痛和麻醉作用。卡瓦最常见的用途是作为一种天然抗焦虑药，在多项研究中与包括苯二氮䓬类在内的多种处方药效果相当。中枢神经系统效应似乎由多种机制介导。关于其与γ-氨基丁酸（GABA）受体结合能力的研究结果存在矛盾，不过在一些研究中发现确实存在这种结合。在体外实验中，已发现卡瓦能阻断去甲肾上腺素的摄取。它还具有一些抗惊厥能力，这似乎是由钠离子通道受体位点介导的。治疗剂量为每日三次，每次50 - 70毫克卡瓦内酯。最常见的副作用通常仅在长期大量使用该草药时出现，是一种称为“卡瓦皮肤病”的鳞状皮疹。已知它还会增强其他药物的作用，如巴比妥类药物和阿普唑仑。
