People in the Pacific Islands, where kava comes from, have probably used kava for thousands of years. First knowledge of it in the West came with one of the expeditions led by Captain James Cook in the 1700s. Natives to the islands used kava as part of important rituals and rites, and it was the focus of many social gatherings. The drink prepared from the roots numbs the mouth. In the 20th century, kava has been given to many important visitors to the Pacific Islands. Hillary Rodham Clinton and Pope John Paul II were given kava during welcoming ceremonies, as were President and Mrs. Lyndon B. Johnson in 1966.

Kava root can reduce stress-related anxiety and the effects of anxiety disorders. At lower dosages, kava helps you be more aware and active, but not tense. At higher dosages, the chemicals in kava root can make you sleepy. But usually, kava is simply calming, as opposed to the heavier sedation of alcohol or anti-anxiety prescription drugs. Health care providers prescribe kava for pain and stiffness, anxiety, insomnia, attention deficit/hyperactivity disorder, uncontrolled epilepsy, pain, and jet lag.

The root comes from a tall shrub that grows in the islands of the Pacific Ocean, including Hawaii. This shrub produces large, green, heart-shaped leaves that grow thickly on the branches, off thick stalks. Long, slender flowers that look like Chinese baby corn grow where the branches meet the stems. The roots look like bundles of woody, hairy branches.

Kava root contains chemicals called kavapyrones, which reduce convulsions and cause muscles to relax in laboratory tests using animals. The kavalactones also cause reactions in the brain that are like those caused by pharmaceutical drugs used for depression and anxiety. Kavalactones are what numbs your tongue if you put liquid kava in your mouth or on your gums.

In some cultures, kava is prepared by chewing the root and spitting it into a bowl. The saliva mixes with the root and activates the plant medicine. Today, manufacturers use alcohol or acetate instead. You can find kava in liquid form, as tinctures or extracts, and in capsules or tablets. It's also available powdered or crushed.

Pediatric

There are no reports to date about the use of kava kava in children. Therefore, use of this herb in children is not recommended at this time.

Adult

If your health care provider has recommended kava, make sure you read the label to look for kava products that are standardized to contain a 70% kavalactone content. A standardized product is one with a listing of specific amounts of active plant material per dosage.

For the relief of anxiety and insomnia, and to reduce stress, the recommended kava dose is 2.0 to 4.0 g as decoction (a preparation made by boiling down the herb in water) up to three times daily. Take 60 to 600 mg kavalactones daily of standardized formulas or follow your provider's instructions.

Length of treatment varies. It may take four weeks before you notice improvement. Recommendations are not to take kava for longer than three months.

Kava's side effects are mild. It can numb the mouth and may have an unpleasant taste. A very small percentage of people report nausea, headache, dizziness, or skin rash when they take kava. If any of these happen to you, make sure you tell your health care provider. The American Herbal Products Association (AHPA) advises pregnant and breast-feeding women not to take kava. It also advises against taking more than the recommended dosage, using kava for longer than three months at a time, and driving while using kava.

Missionaries to the Pacific islands during the 19^th century noticed that people who took kava all the time had yellowish, scaly skin. In a more recent study, people who took 100 times the recommended dose experienced this same yellowing, developed a rash, lost hair, and had trouble with vision, appetite, and breathing. These changes go away when you stop taking kava.

There have also been reports that high doses of kava for prolonged periods of time may cause liver damage. Therefore, you should follow the dosing instructions provided by your healthcare provider or adhere to the recommendations on the product labeling.

Kava may enhance the effects of substances such as barbiturates and other psychopharmacological agents (psychoactive medications). In addition, kava may increase the risk of unpleasant side effects if taken with phenothiazine medications (often used for the treatment of schizophrenia). There has been a case report of an interaction between alprazolam and kava that resulted in coma. Therefore, it is best not to take kava with these medications.

There has been at least one report that kava may reduce the effectiveness of levodopa, a medication used to treat Parkinson's disease. Therefore, you should not take this herb if you are taking any medications containing levodopa.

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