kava-kava(redirected from Tonga)
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Related to Tonga: Rarotonga
kava-kava (Piper Methysticum)(ka-va ka-va) ,
Ava pepper(trade name),
intoxicating pepper(trade name),
Anxiety, stress, restlessness, insomnia, benzodiazepine withdrawalMild muscle aches and painsMenstrual cramps and PMS
ClassificationTherapeutic: antianxiety agents
Alters the limbic system modulation of emotional processes.
Shown to have centrally-acting skeletal muscle relaxant properties activated.
Relief of anxiety.
Absorption: Peak plasma level occurs about 1.8 hr after an oral dose.
Distribution: Enters breast milk.
Metabolism and Excretion: Elimination occurs primarily by renal excretion (both unchanged and metabolites) and in the feces. Metabolized by the liver (reduction or demethylation).
Half-life: Approximately 9 hr.
|PO||1.8 hr||unknown||8 hr|
Contraindicated in: Obstetric / Lactation: Pregnancy (may affect uterine tone) and lactation; Patients with endogenous depression (may ↑ risk of suicide); Children <12 yr; Hepatitis or other liver disease.
Use Cautiously in: Concurrent use of other hepatotoxic agents; Depression and Parkinson's disease (may worsen symptoms); Should not be used for >3 mo to prevent psychological dependence.
Adverse Reactions/Side Effects
Central nervous system
- sensory disturbances
- extrapyramidal effects
Ear, Eye, Nose, Throat
- Pupil dilation
- red eyes
- visual accommodation disorders
- hepatotoxicity (life-threatening)
- gastrointestinal complaints
- allergic skin reactions
- yellow discoloration of skin
- pellagroid dermopathy
- ↓ lymphocytes
- decreased platelets
- weight loss (long term, high dose)
- muscle weakness
InteractionsAdditive effect when used with alprazolam.Potentiates effect of CNS depressants (ethanol, barbiturates, benzodiazepines, opioid analgesics ).Has ↓ effectiveness of levodopa in few cases.May have additive effects with antiplatelet agents.May ↑ risk of liver damage with other hepatotoxic agents.Concurrent use with other hepatotoxic products such as DHEA, coenzyme Q-10 (high doses), and niacin can ↑ risk of liver damage.May have additive sedative effects when used with other herbs with sedative properties.
Oral (Adults) Antianxiety—100 mg (70 mg kavalactones) 3 times daily; Benzodiazepine withdrawal—50–300 mg/day over one week while tapering benzodiazepine over 2 weeks (use 70% kavalactone extract). Insomnia—180–210 mg kavalactones. Typically taken as a tea by simmering the root in boiling water and then straining.
Availability (generic available)
Dried root extracts (alcohol or acetone based) containing 30–70% kavapyrones:
- Assess muscle spasm, associated pain, and limitations of movement prior to and periodically during therapy.
- Assess degree of anxiety and level of sedation (visual disturbances and changes in motor reflexes are side effects) prior to and periodically during therapy.
- Assess sleep patterns and level of sedation upon arising.
- Prolonged use may lead to ↓ of platelet and lymphocyte counts and ↑ liver function tests.
Potential Nursing DiagnosesAnxiety (Indications)
Impaired physical mobility (Adverse Reactions)
Risk for injury (Side Effects)
- Prepared as a drink from pulverized roots, tablets, capsules, or extract.
- Inform patient that significant, serious side effects may occur with prolonged use. Use for longer than 1 mo is not recommended without supervision of health care professional.
- Caution patient to avoid alcohol or other CNS depressants while taking this herb; may increase sedative effect.
- May cause drowsiness. Caution patient to avoid driving or other activities requiring alertness until response to herb is known.
- Warn patients to stop use of the herb immediately if shortness of breath or signs of liver disease (yellowing of the skin or whites of the eyes, brown urine, nausea, vomiting, light-colored stools, unusual tiredness, weakness, stomach or abdominal pain, loss of appetite) occur and contact health care professional.
- Advise patients who have liver disease or liver problems, or persons who are taking drug products that can affect the liver, to consult health care professional before using kava-containing supplements.
- Inform patient that although there is no evidence of physiological dependence, the risk of psychological dependence still exists.
- Advise female patients to use contraception during therapy and to notify health care professional immediately if pregnancy is planned or suspected or if breastfeeding.
- Instruct patient to consult health care professional before taking any Rx, OTC, or other herbal products concurrently with kava-kava.
- Kava has been banned in other countries due to hepatotoxicity.
- Decrease in anxiety level.
- Decrease in muscle spasms.
- Relief of insomnia.