Overview

Kava is a beverage or extract made from the Piper methysticum plant. In the South Pacific, it's a popular drink that is used in ceremonies for relaxation.

The name "kava" comes from the Polynesian word "awa," which means bitter. Kava affects the brain and other parts of the central nervous system. Chemicals called kavalactones that are found in kava are believed to be responsible for its effects.

People commonly use kava for anxiety. It's also used for stress, withdrawal from drugs called benzodiazepines, sleeping problems, and many other purposes, but there is no good scientific evidence to support many of these uses.

Cases of liver damage and even some deaths have been linked to kava use. Because of this, kava was taken off the market in Europe and Canada in the early 2000s. But after reviewing the evidence, most countries have allowed kava to return to the market. Kava was never taken off the market in the US.



Uses & Effectiveness

Possibly Effective for

  • Anxiety. Taking kava by mouth for at least 5 weeks seems to reduce anxiety and might work as well as some prescription anti-anxiety medications.

Possibly Ineffective for

There is interest in using kava for a number of other purposes, but there isn't enough reliable information to say whether it might be helpful.

Side Effects

When taken by mouth: Kava is possibly safe when taken for up to 6 months. Using kava can make it difficult 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.

Kava is possibly unsafe when taken long-term in high doses. It can cause tolerance, dependence, and withdrawal symptoms.

People might have heard that using kava can cause liver damage. This seems to be rare and is most often linked to long-term use of very high doses. Most people who have used kava haven't experienced liver toxicity. Also, past cases of liver toxicity might not be due to kava. Other factors may have contributed to these toxic effects.

Special Precautions and Warnings

When taken by mouth: Kava is possibly safe when taken for up to 6 months. Using kava can make it difficult 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.

Kava is possibly unsafe when taken long-term in high doses. It can cause tolerance, dependence, and withdrawal symptoms.

People might have heard that using kava can cause liver damage. This seems to be rare and is most often linked to long-term use of very high doses. Most people who have used kava haven't experienced liver toxicity. Also, past cases of liver toxicity might not be due to kava. Other factors may have contributed to these toxic effects.

Pregnancy and breast-feeding: Kava is possibly unsafe when taken by mouth while pregnant or breast-feeding. It might affect the uterus while pregnant. Also, some of the chemicals in kava can pass into breast milk and might hurt a breast-fed infant. Avoid using it.

Liver disease: People who have liver problems should avoid kava. It might make liver disease worse.

Parkinson disease: People who have Parkinson disease should avoid kava. It might make this condition worse.

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.

Interactions

    Moderate Interaction

    Be cautious with this combination

  • Haloperidol (Haldol) interacts with Kava

    Haloperidol is broken down by the liver. Kava might decrease how quickly the liver breaks down this medication. This might increase the effects and side effects of haloperidol.

  • Ropinirole (Requip) interacts with Kava

    Ropinirole is broken down by the liver. Kava might decrease how quickly the liver breaks down this medication. This might increase the effects and side effects of ropinirole.

  • Medications changed by the liver (Cytochrome P450 2C19 (CYP2C19) substrates) interacts with Kava

    Some medications are changed and broken down by the liver. Kava might change how quickly the liver breaks down these medications. This could change the effects and side effects of these medications.

  • Medications changed by the liver (Cytochrome P450 1A2 (CYP1A2) substrates) interacts with Kava

    Some medications are changed and broken down by the liver. Kava might change how quickly the liver breaks down these medications. This could change the effects and side effects of these medications.

  • Medications changed by the liver (Cytochrome P450 2C9 (CYP2C9) substrates) interacts with Kava

    Some medications are changed and broken down by the liver. Kava might change how quickly the liver breaks down these medications. This could change the effects and side effects of these medications.

  • Medications changed by the liver (Cytochrome P450 2D6 (CYP2D6) substrates) interacts with Kava

    Some medications are changed and broken down by the liver. Kava might change how quickly the liver breaks down these medications. This could change the effects and side effects of these medications.

  • Medications changed by the liver (Cytochrome P450 3A4 (CYP3A4) substrates) interacts with Kava

    Some medications are changed and broken down by the liver. Kava might change how quickly the liver breaks down these medications. This could change the effects and side effects of these medications.

  • Medications changed by the liver (Cytochrome P450 2E1 (CYP2E1) substrates) interacts with Kava

    Some medications are changed and broken down by the liver. Kava might change how quickly the liver breaks down these medications. This could change the effects and side effects of these medications.

  • Medications moved by pumps in cells (P-Glycoprotein Substrates) interacts with Kava

    Some medications are moved in and out of cells by pumps. Kava might change how these pumps work and change how much medication stays in the body. In some cases, this might change the effects and side effects of a medication.

  • Medications that can harm the liver (Hepatotoxic drugs) interacts with Kava

    Kava might harm the liver. Some medications can also harm the liver. Taking kava along with a medication that can harm the liver might increase the risk of liver damage.

  • Sedative medications (CNS depressants) interacts with Kava

    Kava might cause sleepiness and slowed breathing. Some medications, called sedatives, can also cause sleepiness and slowed breathing. Taking kava with sedative medications might cause breathing problems and/or too much sleepiness.

  • Alcohol (Ethanol) interacts with Kava

    Using kava with alcohol might increase the effects of alcohol on the central nervous system. This might increase the risk for some side effects, such as drowsiness and mood changes. Also, kava might harm the liver. Taking kava along with alcohol might increase the risk of liver damage.

Dosing

Kava is available in many different types of products, including teas and other beverages. Kava extracts have most often been used by adults in doses of 150-400 mg by mouth daily for up to 2 years. Speak with a healthcare provider to find out what type of product and dose might be best for a specific condition.
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CONDITIONS OF USE AND IMPORTANT INFORMATION: This information is meant to supplement, not replace advice from your doctor or healthcare provider and is not meant to cover all possible uses, precautions, interactions or adverse effects. This information may not fit your specific health circumstances. Never delay or disregard seeking professional medical advice from your doctor or other qualified health care provider because of something you have read on WebMD. You should always speak with your doctor or health care professional before you start, stop, or change any prescribed part of your health care plan or treatment and to determine what course of therapy is right for you.

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