Products
In many countries, kava is currently only available in the form of highly diluted homeopathic medicines. For example, Similasan Kava-Kava tablets contain kava in the homeopathic potencies D12, D15 and D30. This remedy no longer contains kava. Mother tinctures and low potencies up to and including D6 may no longer be sold. Previously distributed kava extracts such as kavasedon, laitan or yakona and other phytopharmaceuticals are no longer available. In Germany, sales were allowed again in 2019 under certain conditions.
Stem plant
Kava plant G. Forster (Piperaceae) is a shrub native to the Pacific islands and cultivated, growing about 2-6 m high. The plant was named and described by Johann Georg Forster in the 18th century. is said to translate as “intoxicating drink”. and the synonym or describe the taste of the traditional kava drink and can be translated as bitter, sour, or pungent. Kava refers to both the drink and the kava plant.
Medicinal drug
The kava rhizome, or rootstock, is used as the medicinal drug (kava-kava rhizoma, Piperis methystici rhizoma). The kava drink made from the rhizome traditionally played an important role in the Pacific islands, comparable to alcoholic drinks in Europe. It was consumed in ceremonial, religious, and social occasions, as a stimulant, and as a medicine, among other uses.
Ingredients
The active ingredients are considered to be the kavalactones (kavapyrones), which include kavain, dihydrokavain, methysticin, dihydromethysticin, and yangonin. The extracts used in the past were therefore adjusted to these ingredients. In addition, flavonoids, alkaloids and little essential oil are also found.
Effects
Psychoactive, antianxiety, sedative, relaxant, hypnotic, muscle relaxant, local anesthetic, and antispasmodic effects are attributed to kava preparations. The spectrum of action is thus similar to that of benzodiazepines. The effects have been investigated in clinical trials.
Indications for use
Kava extracts have been approved in many countries as herbal anxiolytics for the treatment of anxiety, agitation, and tension. The marketing authorization of kava kava- and kavain-containing medicinal products, including homeopathic dilutions up to and including D6, was revoked by the Swissmedic medicines agency on June 20, 2003.
Contraindications
Kava extracts should not be taken in endogenous depression, liver disease, risk factors for liver dysfunction, during pregnancy, or lactation. Refer to the drug label for complete precautions.
Interactions
Substances with similar pharmacologic effects, such as alcohol or benzodiazepines, may theoretically potentiate the effects. Kava inhibits CYP450 isozymes and therefore may potentially cause a number of pharmacokinetic interactions. Other interactions have been described (see in Ulbricht et al., 2005).
Adverse effects
Adverse effects include allergic reactions, gastrointestinal discomfort, and mild headache. Cases of extrapyramidal side effects, cardiovascular disturbances, and visual disturbances have been reported. With overdose and chronic use, side effects such as gait disturbances, tremor, sedation, and skin reactions (dry, scaly, yellow skin) are possible. The approval of kava-containing drugs has been withdrawn because some cases of severe liver toxicity have occurred, manifesting as liver failure, cirrhosis, and hepatitis. The mechanism of liver injury has not been fully elucidated, but some hypotheses and studies are available. The kava ban is controversial among phytopharmaceutical experts and pharmaceutical companies, and the question of liver toxicity is still a subject of debate.