Kava is a popular herbal supplement used for the treatment of mild-to-moderate generalized anxiety disorder (GAD). Kava has been shown to cause hepatitis, cirrhosis, and liver failure.
Kava is a popular herbal supplement that originated in the Pacific Islands and has purported benefits in treating anxiety, insomnia, depression, stress, and menopausal symptoms. Traditionally, the roots of the kava plant have been ground up and mixed with water to form a potable liquid. Kavalactones, the active ingredient in kava supplements, interacts with numerous liver enzymes and also may cause direct hepatotoxicity. The FDA recommends that patients with pre-existing liver disease or patients who are taking medications that are predominantly metabolized by the liver, should consult their physician before initiating kava supplementation due to the risk of hepatotoxicity.
Saeed et al. discuss the safety and efficacy of kava for patients with mild anxiety disorders. Kava down-regulates liver enzymes that metabolize many common medications, leading to potential hepatotoxic drug interactions. Certain parts of the kava plant, notably the stems and leaves, may lead to greater toxicity. Physicians supervising patients taking kava should recommend limiting daily dosing to less than 300 mg, avoiding co-prescribing hepatoactive medications, avoiding root-containing kava preparations, and limiting exposure to less than 24 weeks.
Sarris et al. conducted a double-blind, randomized, placebo-controlled study assessing the efficacy of kava for the treatment of generalized anxiety disorder. They found that, among 75 patients monitored for 6 weeks, a significant reduction in anxiety symptoms among patients in the kava group versus the placebo group. With the exception of increased headaches in the kava group, they did not note any difference in adverse events between the two groups, including abnormal liver function tests. Remission rates at the end of 6 weeks were 26% for the kava group versus 6% for the placebo group.
Illustration A shows a picture of the kava plant; commercially available kava supplements are composed of extracted kavalactones, the plant's psychoactive substance.
Answer 2: Gingival hyperplasia is a common adverse effect associated with phenytoin use.
Answer 3: Potentially lethal arrhythmia may occur secondary to consumption of cardiac glycoside plants such as foxglove or oleander.
Answer 4: Seizure may be associated with strychnine, thujone, and essential oils such as camphor or eucalyptus.
Answer 5: Hypertension is an adverse effect associated with licorice toxicity.
Saeed SA, Bloch RM, Antonacci DJ. Safety of kava for patients with mild anxiety disorders. Am Fam Physician. 2008 Aug 15;78(4):433-4.
PMID:18756649 (Link to Abstract)
Sarris J, Stough C, Bousman CA, Wahid ZT, Murray G, Teschke R, Savage KM, Dowell A, Ng C, Schweitzer I. Kava in the treatment of generalized anxiety disorder: a double-blind, randomized, placebo-controlled study. J Clin Psychopharmacol. 2013 Oct;33(5):643-8.
PMID:23635869 (Link to Abstract)