Ava Pepper, Ava Root, Awa, Gea, Gi, Intoxicating Long Pepper, Intoxicating Pepper, Kao, Kavain, Kavapipar, Kawa, Kawa Kawa, Kawa Pepper, Kawapfeffer, Kew, Lawena, Long Pepper, Malohu, Maluk, Maori Kava, Meruk, Milik, Piper methysticum, Poivre des Cannibales, Poivre des Papous, Rauschpfeffer, Rhizome Di Kava-Kava, Sakau, Tonga, Waka, Wurzelstock, Yagona, Yangona, Yaqona, Yaquon, Yongona.
Kava is a beverage or extract that is made from Piper methysticum, a plant native to the western Pacific islands. The name "kava" comes from the Polynesian word "awa," which means bitter. In the South Pacific, kava is a popular social drink, similar to alcohol in Western societies.
There have been some safety concerns about kava. Cases of liver damage and even some deaths have been traced to kava use. Because of these reports, kava was withdrawn from the market in Europe and Canada in the early 2000s. However, in 2012 and 2015, the market withdrawals in Canada and Germany were lifted. These countries decided that there was not enough research to show that kava was the direct cause of liver toxicity in many of these cases. Kava has never been taken off the market in the U.S.
Some people take kava by mouth to calm anxiety, stress, and restlessness, and to treat sleeping problems (insomnia). It is also used for attention deficit-hyperactivity disorder (ADHD), withdrawal from benzodiazepine drugs, epilepsy, psychosis, depression, migraines and other headaches, chronic fatigue syndrome (CFS), common cold and other respiratory tract infections, tuberculosis, muscle pain, and cancer prevention.
Kava is applied to the skin for skin diseases including leprosy, to promote wound healing, and as a painkiller. It is also used as a mouthwash for canker sores and toothaches.
Kava is also consumed as a beverage in ceremonies to promote relaxation.
How does it work?
Kava affects the brain and other parts of the central nervous system. The kava-lactones in kava are believed to be responsible for its effects.
Possibly Effective for...
- Anxiety. Most research shows that taking kava extracts that contain 70% kavalactones can lower anxiety and might work as well as some prescription anti-anxiety medications. Most studies have used a specific kava extract (WS 1490, Dr. Willmar Schwabe Pharmaceuticals). But some inconsistent evidence exists. One reason for the conflicting results may be the duration of treatment. It's possible that treatment for at least 5 weeks is necessary for symptoms to improve. Also, kava might be more effective in people with severe anxiety, in female patients, or in younger patients.
Insufficient Evidence to Rate Effectiveness for...
- Benzodiazepine withdrawal symptoms. Early research suggests that slowly increasing the dose of a specific kava extract ((WS1490, Dr. Willmar Schwabe Pharmaceuticals) over the course of one week while decreasing the dose of benzodiazepines over the course of two weeks can prevent withdrawal symptoms and reduce anxiety in people who have been taking benzodiazepines for a long period of time.
- Cancer prevention. There is some early evidence that taking kava might help to prevent cancer.
- Insomnia. Research on the effectiveness of kava in people with sleeping problems is inconsistent. Some research shows that taking a specific kava extract (WS1490, Dr. Willmar Schwabe Pharmaceuticals) daily for 4 weeks reduces sleeping problems in people with anxiety disorders. But other research suggests that taking kava three times daily for 4 weeks does not reduce insomnia in people with anxiety.
- Menopausal symptoms. Early research shows that taking a specific kava extract (WS1490, Dr. Willmar Schwabe Pharmaceuticals) daily for 8 weeks reduces anxiety and hot flashes in menopausal women. Other research shows that taking kava daily for 3 months might reduce depression, anxiety, and hot flashes.
- Stress. Early research suggests that taking a single dose of kava by mouth might reduce symptoms associated with mentally stressful tasks.
- Attention deficit-hyperactivity disorder (ADHD).
- Chronic fatigue syndrome (CFS).
- Common cold.
- Respiratory tract infections.
- Muscle pain.
- Urinary tract infections (UTIs).
- Swelling of the uterus.
- Sexually transmitted diseases.
- Menstrual problems.
- Sexual arousal.
- Skin diseases.
- Wound healing.
- Other conditions.
Natural Medicines Comprehensive Database rates effectiveness based on scientific evidence according to the following scale: Effective, Likely Effective, Possibly Effective, Possibly Ineffective, Likely Ineffective, and Insufficient Evidence to Rate (detailed description of each of the ratings).
Kava is POSSIBLY SAFE when taken by mouth, short-term. Kava extracts have been used safely under medical supervision for up to 6 months.
People may have heard that use of kava may cause liver damage. The use of kava for as little as 1-3 months has resulted in the need for liver transplants, and even death in some people. Early symptoms of liver damage include yellowed eyes and skin (jaundice), fatigue, and dark urine. However, these cases appear to be relatively rare. Most patients who have used kava have not experienced liver toxicity. Also, some experts believe that the liver toxicity seen in these cases cannot be directly linked to kava. Other factors may have contributed to the toxic effects. To be on the safe side, people who choose to use kava should get liver function tests.
Using kava can make you unable to drive or operate machinery safely. Do not take kava before you plan on driving. "Driving-under-the-influence" citations have been issued to people driving erratically after drinking large amounts of kava tea.
Depression: Kava use might make depression worse.
Liver problems: Kava can cause liver problems even in healthy people. Taking kava if you already have liver disease is taking a risk. People with a history of liver problems should avoid kava.
Parkinson's disease: Kava might make Parkinson's disease worse. Do not take kava if you have this condition.
Surgery: Kava affects the central nervous system. It might increase the effects of anesthesia and other medications used during and after surgery. Stop using kava at least 2 weeks before a scheduled surgery.
Sedative medications (CNS depressants)Interaction Rating: Major Do not take this combination.
Kava might cause sleepiness and drowsiness. Medications that cause sleepiness are called sedatives. Taking kava along with sedative medications might cause too much sleepiness.
Alprazolam (Xanax)Interaction Rating: Moderate Be cautious with this combination.Talk with your health provider.
Kava can cause drowsiness. Alprazolam (Xanax) can also cause drowsiness. Taking kava along with alprazolam (Xanax) may cause too much drowsiness. Avoid taking kava and alprazolam (Xanax) together.
Haloperidol (Haldol)Interaction Rating: Moderate Be cautious with this combination.Talk with your health provider.
Haloperidol (Haldol) is broken down by the liver. Kava might decrease how quickly the liver breaks down this medication, which might increase side effects. There is a report of heart complications following haloperidol injections in a patient who was also taking kava by mouth.
LevodopaInteraction Rating: Moderate Be cautious with this combination.Talk with your health provider.
Levodopa affects the brain by increasing a brain chemical called dopamine. Kava might decrease dopamine in the brain. Taking kava along with levodopa might decrease the effectiveness of levodopa.
Medications changed by the liver (Cytochrome P450 1A2 (CYP1A2) substrates)Interaction Rating: Moderate Be cautious with this combination.Talk with your health provider.
Some medications are changed and broken down by the liver. Kava might decrease how quickly the liver breaks down some medications. Taking kava along with some medications that are changed by the liver might increase the effects and side effects of some medications. Before taking kava, talk to your healthcare provider if you take any medications that are changed by the liver.
Some of these medications that are changed by the liver include clozapine (Clozaril), cyclobenzaprine (Flexeril), fluvoxamine (Luvox), haloperidol (Haldol), imipramine (Tofranil), mexiletine (Mexitil), olanzapine (Zyprexa), pentazocine (Talwin), propranolol (Inderal), tacrine (Cognex), theophylline, zileuton (Zyflo), zolmitriptan (Zomig), and others.
Medications changed by the liver (Cytochrome P450 2C19 (CYP2C19) substrates)Interaction Rating: Moderate Be cautious with this combination.Talk with your health provider.
Some medications are changed and broken down by the liver. Kava might decrease how quickly the liver breaks down some medications. Taking kava along with some medications that are broken down by the liver can increase the effects and side effects of your medication. Before taking kava, talk to your healthcare provider if you take any medications that are changed by the liver.
Some of these medications changed by the liver include amitriptyline (Elavil), clomipramine (Anafranil), cyclophosphamide (Cytoxan), diazepam (Valium), lansoprazole (Prevacid), omeprazole (Prilosec), lansoprazole (Protonix), phenytoin (Dilantin), phenobarbital (Luminal), progesterone, and others.
Medications changed by the liver (Cytochrome P450 2C9 (CYP2C9) substrates)Interaction Rating: Moderate Be cautious with this combination.Talk with your health provider.
Some medications are changed and broken down by the liver. Kava might decrease how quickly the liver breaks down some medications. Taking kava along with some medications that are broken down by the liver can increase the effects and side effects of some medications. Before taking kava, talk to your healthcare provider if you take any medications that are changed by the liver.
Some medications that are changed by the liver include amitriptyline (Elavil), diazepam (Valium), zileuton (Zyflo), celecoxib (Celebrex), diclofenac (Voltaren), fluvastatin (Lescol), glipizide (Glucotrol), ibuprofen (Advil, Motrin), irbesartan (Avapro), losartan (Cozaar), phenytoin (Dilantin), piroxicam (Feldene), tamoxifen (Nolvadex), tolbutamide (Tolinase), torsemide (Demadex), warfarin (Coumadin), and others.
Medications changed by the liver (Cytochrome P450 2E1 (CYP2E1) substrates)Interaction Rating: Moderate Be cautious with this combination.Talk with your health provider.
Some medications are changed and broken down by the liver. Kava might decrease how quickly the liver breaks down some medications. Taking kava along with some medications that are changed by the liver can increase the effects and side effects of your medication. Before taking kava, talk to your healthcare provider if you take any medications that are changed by the liver.
Some medications that are changed by the liver include acetaminophen, chlorzoxazone (Parafon Forte), ethanol, theophylline, and drugs used for anesthesia during surgery such as enflurane (Ethrane), halothane (Fluothane), isoflurane (Forane), and methoxyflurane (Penthrane).
Medications changed by the liver (Cytochrome P450 3A4 (CYP3A4) substrates)Interaction Rating: Moderate Be cautious with this combination.Talk with your health provider.
Some medications are changed and broken down by the liver. Kava might decrease how quickly the liver breaks down some medications. Taking kava along with some medications that are broken down by the liver can increase the effects and side effects of some medications. Before taking kava, talk to your healthcare provider if you are taking any medications that are changed by the liver.
Medications moved by pumps in cells (P-Glycoprotein Substrates)Interaction Rating: Moderate Be cautious with this combination.Talk with your health provider.
Some medications are moved by pumps in cells. Kava might make these pumps less active and increase how much of some medications get absorbed by the body. This might increase the amount of some medications in the body, which could lead to more side effects. But there is not enough information to know if this is a big concern.
Some medications that are moved by these pumps include etoposide, paclitaxel, vinblastine, vincristine, vindesine, ketoconazole, itraconazole, amprenavir, indinavir, nelfinavir, saquinavir, cimetidine, ranitidine, diltiazem, verapamil, corticosteroids, erythromycin, cisapride (Propulsid), fexofenadine (Allegra), cyclosporine, loperamide (Imodium), quinidine, and others.
Medications that can harm the liver (Hepatotoxic drugs)Interaction Rating: Moderate Be cautious with this combination.Talk with your health provider.
Kava might harm the liver. Taking kava along with medication that might also harm the liver can increase the risk of liver damage. Do not take kava if you are taking a medication that can harm the liver.
Some medications that can harm the liver include acetaminophen (Tylenol and others), amiodarone (Cordarone), carbamazepine (Tegretol), isoniazid (INH), methotrexate (Rheumatrex), methyldopa (Aldomet), fluconazole (Diflucan), itraconazole (Sporanox), erythromycin (Erythrocin, Ilosone, others), phenytoin (Dilantin), lovastatin (Mevacor), pravastatin (Pravachol), simvastatin (Zocor), and many others.
Ropinirole (Requip)Interaction Rating: Moderate Be cautious with this combination.Talk with your health provider.
Ropinirole (Requip) is broken down by the liver. Kava might decrease how quickly the liver breaks down this medication, which might increase side effects. There is a report of hallucinations and delusions in a patient who used kava together with Ropinirole (Requip).
Medications changed by the liver (Cytochrome P450 2D6 (CYP2D6) substrates)Interaction Rating: Minor Be cautious with this combination.Talk with your health provider.
Some medications are changed and broken down by the liver. Kava might decrease how quickly the liver breaks down some medications. Taking kava along with some medications that are changed by the liver can increase the effects and side effects of your medication. Before taking kava, talk to your healthcare provider if you take any medications that are changed by the liver.
Some medications that are changed by the liver include amitriptyline (Elavil), clozapine (Clozaril), codeine, desipramine (Norpramin), donepezil (Aricept), fentanyl (Duragesic), flecainide (Tambocor), fluoxetine (Prozac), meperidine (Demerol), methadone (Dolophine), metoprolol (Lopressor, Toprol XL), olanzapine (Zyprexa), ondansetron (Zofran), tramadol (Ultram), trazodone (Desyrel), and others.
The following doses have been studied in scientific research:
- For Anxiety: 50-100 mg of a specific kava extract (WS 1490, Dr. Willmar Schwabe Pharmaceuticals), taken three times daily for up to 25 weeks, has been used. Also, 400 mg of another specific kava extract (LI 150, Lichtwer Pharma) taken daily for 8 weeks has been used. Five kava tablets each containing 50 mg of kavalactones have been taken in three divided doses daily for one week. One to two kava extract tablets has been taken twice daily for 6 weeks. Calcium supplements plus 100-200 mg of kava taken daily for 3 months has also been used.
Report Problems to the Food and Drug Administration
You are encouraged to report negative side effects of prescription drugs to the FDA. Visit the FDA MedWatch website or call 1-800-FDA-1088.
Assessment of the Risk of Hepatotoxicity with Kava Products. 2000;
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