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anxiolytic drug buspirone (Buspar). However, concerns about potential liver toxicity are
emphasized.
The Natural Standard rates use of kava for insomnia and stress “C,” “unclear scientific
evidence for this use.”
- DRUG INTERACTIONS:
- Taking kava with alcohol, other sedatives, or muscle relaxants can result in additive
effects up to and including coma. Kava may interact with several drugs, including drugs
used for Parkinson's disease and benzodiazepines used for anxiety. Alcohol or
acetaminophen (Tylenol), which may injure the liver, are strongly contraindicated for
use with kava. Kava may interfere with the effects of dopamine and drugs that are
similar to dopamine and may worsen the neurological side effects of drugs that block
dopamine such as haloperidol (Haldol).
- Kava may have chemical properties similar to monoamine oxidase inhibitors
("MAOIs"), and may be additive to the effects of MAOI antidepressants, such as
isocarboxazid (Marplan), phenelzine (Nardil), or tranylcypromine (Parnate). Thus, kava
should never be used with MAOIs. Adjunctive use with other psychotropic drugs,
including tricyclic antidepressants and SSRIs, has not been tested, but should not be
attempted without careful coordination with the prescribing physician. Kava may
cause excessive drowsiness when taken with SSRI antidepressant drugs such as
fluoxitine or sertraline. Kava may also cause anesthesia to last longer and use should be
carefully coordinated with the prescribing physician or anesthesiologist.
- Laboratory tests suggest a danger of bleeding, but this has not yet been found in human
subjects. Still, Natural Standard cautions against using anticoagulants or antiplatelets
with kava. This includes warfarin (Coumadin), heparin, aspirin, and clopidogrel (Plavix).
- Since kava has diuretic properties, it may have an additive effect when taken with
diuretic drugs such as furosemide or with ACE inhibitors such as benazopril or captopril.
The Natural Standard specifically cautions avoidance of kava, in patients with
Parkinson's disease or those with a “history of medication-induced extrapyramidal
