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Since May 10th 2008

Initial P

Paeonia lactiflora
Panax ginseng
Plantago afra
Platycodon grandiflorum
Piper methysticum
Polygala senega
Prunus africana
Prunus armeniaca
Plantago ovata
Pimpinella anisum
Passiflora incarnata
Psidium guajava
Punica granatum



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Piper methysticum G. Forst. (Piperaceae)

Macropiper latifolium Miq., M. methystiscum (G. Forst.) Hook. et Arnott, Piper inebrians Soland

Local names
Ava, ava root, awa, gea, gi, kao, kava, kavakava, kava-kava, kava-kava root, kavapipar, kawa, kawa kawa, kawa pepper, Kawapfeffer, malohu, maluk, maori kava, meruk, milik, racine de poivre enivrant, Rauschpfeffer, rhizoma de kava-kava, rhizoma di kava-kava, yagona, yaqona

A perennial shrub up to 7m high, robust and fairly succulent. Leaves cordate, pointed, smooth and green on both sides, up to 25 cm long. Root can reach 60cm in length and 8 cm in diameter; may eventually become a heavy knotted mass, 8–25 cm wide. Petioles up to 6 cm long; flowers in irregular spadices with lateral root up to 3m long

Plant material used
dried rhizome

Chemical assays
Contains not less than 3.5% kava pyrones, as determined by infrared absorption spectroscopy at 1705 ± /5cm. Complete qualitative analytical profiles can be obtained by high-performance liquid chromatography–electrospray mass spectrometry. A high-performance liquid chromatography method is also available for quantitative analysis

Major chemical constituents
The major constituents are kava lactones (also known as kava pyrones) with the major lactones being kawain (1.8%), methysticin (1.2%), dihydromethysticin (0.5%), demethoxyyangonin (1.0%), yangonin (1.0%) and dihydrokawain (1.0%). At least 13 other lactones, two chalcones and a number of free aromatic acids are known

Medicinal uses
Uses supported by clinical data
Short-term symptomatic treatment of mild states of anxiety or insomnia, due to nervousness, stress or tension.

Uses described in pharmacopoeias and well established documents
To induce relaxation, reduce weight and treat fungal infections.

Uses described in traditional medicine
Treatment of asthma, common cold, cystitis, gonorrhoea, headaches, menstrual irregularities, urinary infections and warts

Proven pharmacological activity
Animal studies
Analgesic, CNS depressant, Neuroprotective, Anticonvulsant, Antispasmodic, Antimicrobial

Human studies
Treatment of anxiety, Treatment of insomnia

During pregnancy and lactation, and in patients with endogenous depression or liver disease.

Rhizoma Piperis Methystici should not be taken for more than 3 months without medical advice. Even when administered within the recommended dosage range, motor reflexes and the ability to drive or operate heavy machinery may be adversely affected.

Drug interactions
The effectiveness of centrally acting drugs such as alcohol, barbiturates and other psychopharmacological agents may be potentiated. One case of possible drug interaction between Rhizoma Piperis Methystici, alprazolam, cimetidine and terazosin has been reported. The clinical significance of this interaction has not yet been established.

Carcinogenesis, mutagenesis, impairment of fertility
Oral administration of up o 600 mg/kg body weight of a standardized extract containing 70% kava pyrones did not increase the formation of micronucleated polychromatic erythrocytes and did not lead to any change in the ratio of polychromatic to normochromatic erythrocytes. There was no increase in the number of revertants in Salmonella typhimurium strains TA98, TA100, TA1535, TA1537 and TA1538 with or without metabolic activation, at doses up to 2.5 mg/plate in the Salmonella/microsome assay.

Pregnancy: teratogenic effects
See Contraindications.

Pregnancy: non-teratogenic effects
See Contraindications

Nursing mothers
See Contraindications.

Other precautions
No information available on general precautions or precautions concerning drug interactions; drug and laboratory test interactions; or paediatric use. Therefore, Rhizoma Piperis Methystici should not be administered to children without medical supervision.

Adverse reactions
In a surveillance study involving 4049 patients who received a standardized extract of Rhizoma Piperis Methystici containing 70% kava pyrones (150mg extract, equivalent to 105 mg kava pyrones) orally daily for 7 weeks, adverse reactions were reported in 61 patients (1.5%). The major reactions were gastrointestinal complaints or allergic skin reactions. In a study of 3029 patients given a standardized extract of the rhizome containing 30% kava pyrones (800 mg extract, equivalent to 240 mg kava pyrones) orally daily for 4 weeks, adverse reactions were reported in 2.3% of patients. Nine cases of allergic reactions, 31 cases of gastrointestinal complaints, 22 cases of headache or dizziness, and 11 cases of other undefined problems were reported. Chronic administration of the rhizome or preparations thereof may cause atransient, yellow discoloration of the skin and nails, which is reversible upon discontinuation of the drug. Excessive, chronic abuse of infusions of the rhizome has been historically associated with a scaly, eruptive dermopathy of unknown etiology. Allergic skin reactions and ichthyosis have also been reported. In two patients, a reaction was seen in areas rich in sebaceous glands following 3 weeks of systemic antidepressant therapy with the rhizome. The reaction resulted in the formation of papules and plaques on the face, and ventral and dorsal thorax. One study in an Australian aboriginal community found that chronic abuse of the rhizome led to malnutrition and weight loss, increased levels of g-glutamyltransferase, decreased levels of plasma protein, and reduced platelet volume and lymphocyte numbers. In a healthy volunteer, disturbances of visual accommodation, such as enlargement of the pupils, and disturbances in oculomotor equilibrium, were reported following the ingestion of large doses of kava. Chronic consumption (6 months) of large quantities of an infusion of the rhizome (5–6 cups daily) has been reported to cause anorexia, diarrhoea and visual disturbances. A single case report of athetosis involving the limbs, trunk, neck and facial musculature, with marked athetosis of the tongue, was associated with chronic consumption of large quantities of the rhizome. There is one report of acute hepatitis in a 39-year-old woman following ingestion of a rhizome preparation. However, the identity of the material was not authenticated.

Dosage forms
Comminuted crude drug and extracts for oral use. Store in a tightly closed container, away from light.

(Unless otherwise indicated)
Daily dosage: crude drug and extracts equivalent to 60–210mg kava pyrones


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