Natural Medicines Newsletter

Volume 1, Issue 32, 08/27/2009

Question

Is kava (Piper methysticum) safe and effective for the treatment of anxiety disorders?

Answer

Anxiety disorders are common medical conditions and many healthcare providers will encounter them in clinical practice.  They generally affect people in the first 3 decades of life.  Within anxiety disorders, the one year prevalence for social anxiety disorder (SAD) is 6.8%, generalized anxiety disorder (GAD) is 3.1%, and panic disorder is 2.7%.¹  Unfortunately, many patients do not receive adequate treatment and thus may resort to the use of over-the-counter (OTC) supplements such as kava (Piper methysticum) to relieve their symptoms.^2,3  Kava is a member of the pepper family that is native to the South Pacific and has been reported to be useful for anxiety.⁴  Of greatest concern are patients who choose to treat their anxiety with both a kava supplement and benzodiazepine that was prescribed by their physician or patients who fail to inform their physician of their use of kava extract at the point when standard doses of a benzodiazepine are initiated.  An example of the dangers of this combination are illustrated in a case report describing a patient that was admitted to the hospital in a semicomatose state after 3 days of simultaneous use of kava and alprazolam.³  The mechanism by which the use of a benzodiazepine and kava together can result in central nervous system (CNS) depression has been covered in a previous issue.⁵  The question for this issue relates to data demonstrating the safety and efficacy of kava for treatment of anxiety.