Kava for the treatment of generalized anxiety disorder RCT: analysis of adverse reactions, liver function, addiction, and sexual effects

Phytother Res. 2013 Nov;27(11):1723-8. doi: 10.1002/ptr.4916. Epub 2013 Jan 24.

Abstract

Presently, little is known about a number issues concerning kava (Piper methysticum), including (i) whether kava has any withdrawal or addictive effects; (ii) if genetic polymorphisms of the cytochrome (CYP) P450 2D6 liver enzyme moderates any potential adverse effects; and (iii) if medicinal application of kava has any negative or beneficial effect on sexual function and experience. The study design was a 6-week, double-blind, randomized controlled trial (n = 75) involving chronic administration of kava (one tablet of kava twice per day; 120 mg of kavalactones per day, titrated in non-response to two tablets of kava twice per day; 240 mg of kavalactones) or placebo for participants with generalized anxiety disorder. Results showed no significant differences across groups for liver function tests, nor were there any significant adverse reactions that could be attributed to kava. No differences in withdrawal or addiction were found between groups. Interesting, kava significantly increased female's sexual drive compared to placebo (p = 0.040) on a sub-domain of the Arizona Sexual Experience Scale (ASEX), with no negative effects seen in males. Further, it was found that there was a highly significant correlation between ASEX reduction (improved sexual function and performance) and anxiety reduction in the whole sample.

Keywords: Piper methysticum; anxiety; kava; liver function; safety; sexual function.

Publication types

  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Anti-Anxiety Agents / adverse effects
  • Anti-Anxiety Agents / pharmacology
  • Anti-Anxiety Agents / therapeutic use*
  • Anxiety Disorders / chemically induced
  • Anxiety Disorders / drug therapy*
  • Cytochrome P-450 CYP2D6 / genetics
  • Double-Blind Method
  • Female
  • Humans
  • Kava*
  • Lactones / pharmacology
  • Lactones / therapeutic use
  • Liver / drug effects
  • Liver / enzymology
  • Liver Function Tests
  • Male
  • Middle Aged
  • Phytotherapy*
  • Sexual Dysfunction, Physiological / chemically induced
  • Young Adult

Substances

  • Anti-Anxiety Agents
  • Lactones
  • Cytochrome P-450 CYP2D6