- Indications with possible efficacy:
Anxiety, nervousness (popular use)
Anxiety related to menopause
- Indications with possible, but poorly documented efficacy :
Insomnia (popular use)
- Indications with no proof of efficacy:
Chronic urinary infections
Sexually transmitted diseases (STDs)
Wound healing (topical)
- Risk of Drug Interactions: Moderate
- Adverse Effects: Not Frequent
Part of the plant used: roots and rhizomes
Kava is a shrub, 3 meters or taller, that grows in the Pacific islands of Micronesia, Polynesia, Indonesia and New-Guinea. While it does blossom, it cannot reproduce by itself and needs man's help to propagate. The applicable part of kava is the root, from which kavalactones are extracted. Kavalactones are thought to be responsible for kava's effects. Because the kavalactone content may vary from 3 to 20%, standardized kavalactone preparations are preferred to crude extracts. Polynesians are still using kava for its "magical" properties during ceremonies and celebrations: it apparently calms those who take it and increases their sociability.
Direction of use
- Anxiety, nervousness:
There is evidence that kava can effectively treat anxiety, nervousness, and stress. One to 8 weeks may be needed to obtain results, but it should not be used for more than three months, since long-term, high-dose use may be associated with poor health.
Used doses: 70 mg of kavalactones, 3 times a day.
Will induce sleep in about 30 minutes. No residual effects compared with alcohol or benzodiazepine.
Used doses: 80 mg to 160 mg ate bedtime.
There is insufficient reliable information to conclude that kava is effective in any other indication, including topical application.
- Side effects
Kava may cause gastrointestinal upset, headache, dry mouth and dizziness. It may also cause hepatic problem. A prolonged use might cause a skin reaction.
Avoid in depressed patients, with Parkinson's disease and liver disease. Kava may affect the ability to drive. Not recommended for longer than 3 months.
Concomitant use with hepatotoxic drugs might increase the risk of developing liver damage. Kava is also thought to increase the effect of central nervous system depressant agents and decrease the effect of levodopa used in Parkinson's disease. Before taking kava, check with your pharmacist to make sure that there are no interactions with your regular medication.
- Pregnancy and lactation
Kava is contraindicated in pregnancy and during breast-feeding.
In 2004, Canada adopted new regulations that control the manufacturing, packaging, labeling and importing of natural health products. The new regulations also include an adverse reaction reporting system. Products that conform to the regulation's criteria are identified with a natural product number (NPN) and can be legally sold in Canada. This number indicates that the product meets specific criteria for safety and purity, not that it is effective for any indication.
Medicinal plant contents vary naturally from plant to plant - just as fruits from the same package may vary in taste and texture. There is no standard to measure the active content of each plant. Thus, efficacy of natural products should be expected to vary from brand to brand as well as from bottle to bottle of the same brand.
For more information about the Natural Health Products Regulations, or to check if a product has been assessed, visit the Health Canada website at www.hc-sc.gc.ca/dhp-mps/prodnatur/index-eng.php.
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- Health Canada - Advisory #21 Augustt 2002
- Passeportsanté.net. Kava. www.passeportsante.net
- Rotblatt M. et Ziment I. Evidence-Based Herbal Medicine, Hanley & Belfus, 2002
- Herbal Companion to AHFS DI, American Society of Health-System Pharmacists, 2001
- Taylor J. CE: Phytomedicinals: Uses, precautions, and drug interactions. Drug Topics 2003;1:79
- Natural Therapeutics Pocket Guide, 2000-2001
- The Review of Natural Products, 6th Edition, 2010
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The patient information leaflets are provided by Vigilance Santé Inc. This content is for information purposes only and does not in any manner whatsoever replace the opinion or advice of your health care professional. Always consult a health care professional before making a decision about your medication or treatment.