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Kava kava
(Piper methysticum)
DESCRIPTION
Kava kava is a member of the pepper family. Kava has been
used in native medicine for its relaxing qualities, for urinary
tract Infections, Asthma, as a topical anaesthetic, and other
applications. The primary interest in the West has been its
well-documented anxiolytic effects (1). Kava is a herb that
has enjoyed respect in the islands of the South Pacific and
has been used as a ritual beverage for ceremonial purposes,
including the welcoming of important guests (1). The rhizome
is the part used: it is chewed or ground with a pestle to
produce a cloudy, milky mash. Saliva is added on chewing,
causing enzymatic degradation, the productions of which give
the full intoxicating effect. Having taken their kava drink,
people feel calm and relaxed, with mental activity enhanced.
Kava does not appear to have narcotic properties (2).
HERBAL USES
Kava has been specifically
used in the treatment of nervous Anxiety, Insomnia, Depression
and restlessness, through its sedative and anxiolytic properties.
SUGGESTED INTAKES
Part of the plant used:
ROOTSTOCK (RHIZOME).
Herb powder 235-700mg three times daily.
The appropriate amount of kava preparation taken depends on
the level of kavalactones. On the basis of clinical studies
using pure kavalactones or kava extracts standardised for
kavalactones, the dosage recommendation for anxiolytic effects
is 45 to 70mg of kavalactones three times daily. For sedative
effects, a dose providing 180 to 210mg of kavalactones can
be taken one hour before retiring (3).
SUPPLEMENTAL USES
Kava root is primarily used
as a natural sedative and sleep enhancement. Herbalists have
traditionally used it as a remedy for Nervousness and Insomnia.
Kava is an effective relaxant able to induce a feeling of
relaxation, peace and contentment, along with a sharpening
of the senses. As a sleep aid it promotes deep and restful
sleep. It is also a muscle relaxant that may help relieve
cramping due to spasms.
Kava has been used for cystitis,
urethritis, rheumatism, joint pains, and Infection of the
genitourinary tract, Headache and nervous exhaustion.
Kava affects motor and muscular function, while mental function
appears to remain clear (1).
Kava may be helpful in the
management of menopausal problems (1).
SAFETY AND PRECAUTIONS
High intakes of kava over
a prolonged period is associated with "kava dermopathy"
a scaly eruption of the Skin. The skin becomes dry, yellowy
and covered with scales, especially the palms of the hands,
soles of the feet, forearms, the back and shins (4).
It was thought that kava
dermopathy may be due to interference with Niacin
. However, in one study no therapeutic effect with Niacin
amide could be demonstrated (5).
Kava extract should not
be used in Parkinson’s Disease, as it may interfere
with dopamine production or binding to receptor sites and
worsen the disease. Kava exerts an additive effect when combined
with bensodiazepines (6).
Kava in high doses increases central nervous Depression and
relaxation of skeletal muscle (2).
Following high doses of kava (more than 310g per week) for
prolonged periods, adverse effects include biochemical abnormalities
- low levels of serum albumin, protein, urea and bilirubin.
The presence of blood in the urine, increased red blood cell
volume, decreased platelet and lymphocyte counts and shortness
of breath (7).
With long term use of kava, there may also be accommodative
disturbances, such as enlargement of the pupils and disturbances
of the oculomotor equilibrium (1).
Kava may adversely affect
motor reflexes and judgement for driving and/or operating
heavy machinery, especially when taken above the recommended
dosage (1).
Kava should not be taken
for more than three months without medical advice (1).
Kava is not recommended
for use by persons under the age of 18 (1).
Kava is not recommended
for use during Pregnancy or lactation (1).
RESEARCH STUDIES
Standardised preparations
of kava are now gaining great popularity in Europe and the
United States as a mild sedative and anxiolytics (3).
Many of the first comprehensive
studies on the activities of kavalactones were conducted by
a team of scientists from the Freiburg University Institute
of Pharmacology in Germany, led by Hans J. Meyer, during the
1950s and 1960s. This research has determined that kavalactones
exhibit sedative, analgesic, anticonvulsant, and muscle relaxant
effects (1). More recent studies, have confirmed and/or elaborated
on these effects (3).
REFERENCES
1. Herbal Medicine,
2000, Expert Committee of the German Federal Institute for
Drugs and Medical Devices.
2. Herbal Medicine, 1998, Rudolf Fritz Weiss MD. Beaconsfield
Arcanum. 1988.
3. The Healing Power of herbs, Michael T Murray N.D. Prima
1995.
4. Journal of American Academy of Dermatology, 1994, 31; 89-87.
5. Lancet, 1990, 335; 1442-1445.
6. Encylopedia of Natural Medicine, Michael T Maurray N. D.
and Joseph Pizzorno N.D. Little, Brown and Company. 1998.
7. Medical Journal of Australia, 1988, 148: 548-555.
8. Arzneim Forsch, 1991, 41; 584-588.
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