• Basic Info
• Top Questions
• Interactions

Interactions

Interactions with Drugs

Based on multiple human reports of liver toxicity, including hepatitis, cirrhosis, and liver failure, a theoretical increased risk of liver damage may occur if kava is taken with drugs that may injure the liver such as alcohol or acetaminophen (Tylenol®).

In theory, kava may increase the effects of alcohol or other drugs that cause sedation (drowsiness). In theory, kava may interfere with the effects of dopamine or drugs that are similar to dopamine, and may worsen the neurologic side effects of drugs that block dopamine such as haloperidol (Haldol®).

Kava may have chemical properties similar to monoamine oxidase inhibitors (MAO-I). In theory, kava may add to the effects of MAO-I antidepressants, such as isocarboxazid (Marplan®), phenelzine (Nardil®), or tranylcypromine (Parnate®). Due to this possible effect, kava may also cause the effects of anesthesia to last longer, and some practitioners recommend stopping kava two to three days before surgery.

Laboratory tests suggest that kava may increase the risk of bleeding through effects on blood platelets. However, human evidence is lacking in this area. People using aspirin, anticoagulants ("blood thinners") such as warfarin (Coumadin®) and heparin, or anti-platelet drugs such as clopidogrel (Plavix®) should be aware of possible interactions.

Since kava has diuretic properties, it may have additive effects when taken with diuretic drugs such as furosemide or with ACE inhibitors such as benazepril or captopril. Avoid in Parkinson's disease or in patients with a history of medication-induced extrapyramidal effects because kava may cause additive effects. Kava may cause excessive drowsiness when taken with SSRI antidepressant drugs such as fluoxetine or sertraline. Buspirone and opipramol may have additive effects when taken with kava.

Preliminary evidence shows that kava may interfere with the way the body processes certain drugs using the liver's "cytochrome P450" enzyme system. As a result, the levels of these drugs may be altered in the blood, and may cause different effects or potentially serious adverse reactions.

Interactions with Herbs & Dietary Supplements

Based on multiple human reports of liver toxicity, including hepatitis, cirrhosis, and liver failure, a theoretical increased risk of liver damage may occur if kava is taken with herbs or supplements that may injure the liver.

In theory, kava may increase the sedation (drowsiness) caused by some herbs and supplements.

Kava may have chemical properties similar to antidepressant drugs monoamine oxidase inhibitors (MAO-I) and therefore may interact with herbs and supplements with similar effects.

Based on laboratory tests, it is suggested that kava may increase the risk of bleeding through effects on blood platelets. However, human evidence is lacking in this area. People using other herbs or supplements that may increase the risk of bleeding should speak with a healthcare professional before starting kava.

Nausea, sweating, muscle cramping, weakness and increased pulse and blood pressure has been reported after a single dose of combination St. John's wort, kava, and valerian.

Since kava has diuretic properties, it may have additive effects when taken with diuretic herbs or supplements like horsetail or licorice.

Preliminary evidence shows that kava may interfere with the way the body processes certain herbs or supplements using the liver's "cytochrome P450" enzyme system. As a result, the levels of other herbs or supplements to be too high in the blood.