As we know, kava has
been an important social, ritual, and medicinal drink in many Pacific Island cultures for
centuries, and it's use is extremely well documented by casual observers and scientists
(anthropologists, sociologists) alike. Thus, a good case can be made for defining kava as
GRAS, the medical term for "generally recognized as safe." According to the
Commission E Report (see Chapter 8), when taken as a standardized extract in the medicinal
doses typically prescribed for stress and anxiety, kava possesses no known side effects or
toxic consequences.
Safety and the Commission E ReportBack to Top
In Chapter 8, the Commission E
Monograph addresses various safety concerns, including contraindications, duration, and
interactions with other drugs. Following, we elaborate on these safety issues.
Contraindications
According to Commission E, "Kava should not be used during pregnancy,
nursing, and endogenous depression." These warnings should be followed; however, for
clarification, there have been no published reports of any birth defects, nor any adverse
effects in infants of nursing mothers taking kava. Also, as noted later in this chapter,
there were no fetal abnormalities found in high dose animal studies. In terms of
endogenous depression, this is referring to a more severe form of depression, which may
become worse with any antianxiety or calming substance. Mild depressive symptoms, on the
other hand, can actually benefit from kava, as shown in the studies in Chapter 8.
Duration
According to Commission E, "Kava should not be taken for more than three
months without medical advice." This three-month limit refers to continuous use only,
not when taken on an "as needed" basis, which can be done without this
restriction. (Kava's advantages for these purposes are that it begins to work immediately,
and has no withdrawal problems.) We see, from research, that kava is useful for
longer-term continuous treatment. For example, the patients in Volz's 1997 study did well
over the six-month course, with minimal side effects (fewer than the placebo group).
Interactions with Other Drugs
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According to Commission E,
"Potentiation of effectiveness is possible for substances acting on the central
nervous system, such as alcohol, barbiturates, and psychopharmaco
logical agents." A common question is "Can I take kava while I'm taking
benzodiazepines or other pharmaceutical antianxiety or antidepressant medication?"
Unlike St. John's wrote, which can be safely combined with medication during transition
under medical supervision, the situation with kava is less clear. In Germany, kava and
medication are used together during this transition, with no reported problems. However,
this is under the supervision of physicians with experience in this use, and who are
taking appropriate precautions. Since we have been unable to establish with certainty the
safety of taking kava with the pharmaceuticals, we recommend that you follow a prudent
path and start taking kava only after you have discontinued the pharmaceutical.
It has been reported that kava "potentiates" (i.e., increases) the sedative
effects of barbiturates. In studies done with mice, the kavalactone dihydromethysticin had
the greatest effect in this regard (see Chapter 7).We may not be able to extrapolate
directly to humans, as demonstrated by the conflicting results between rodents and humans
in the kava/alcohol studies described later in this chapter. Further investigation,
including more human studies, is needed to answer the questions about kava-drug
interaction. Since there may be issues here regarding the safety of such studies, we can
start by reviewing any existing information on cases where kava has been mixed with
medication.
One report of a possible interaction between kava and a benzodiazepine (Xanax), appears in
the dramatically entitled letter to the editor: "Coma from the Health Food Store:
Interaction Between Kava and Alprazolam [Xanax]." In the article, doctors describe a
54-year-old male who was admitted to the hospital "in a lethargic and disoriented
state" (not in a coma, as the headline states). Moreover, despite the mental
impairment, his vital signs (pulse, blood pressure, and temperature) were normal. He
recovered within several hours. In addition to taking kava for three days prior, along
with continuous use of Xanax (alprazolam), he had also been taking cimetidine (Tagamet)
and terazosin (Hytrin).1
Xanax is a short-acting benzodiazepine, commonly prescribed for anxiety. There is
certainly a possibility of potentiation between the Xanax and kava, though we are not
certain how strongly kava affects the GABA binding sites, the sites of action of the
benzodiazepines. We have already seen how kava potentiates the sedative effects of
barbiturates. However, Germany's Dr. Werner Busse, of the Schwabe Pharmaceutical Co.
(manufacturers of the kava), was of the opinion that the Xanax itself can cause
accumulation and intensify side effects, as could the other medications. He also noted,
referring to conventional medical journals in the United States, that "they seem to
be eagerly accepting poorly substantiated and documented reports of possible side effects
of botanicals, while being rather reluctant in the past to accept reports on the efficacy
of botanicals."
Since kava potentiates the sedative effects of barbiturates, then the possibility of drug
interactions between kava and most CNS depressants could be expected. It is reasonable,
then, to avoid combining kava and benzodiazepines. If you are currently taking
pharmaceuticals and wish to stop, consult your physician or find one who will work with
you to shift to herbal treatment. Follow a prudent path to transition yourself from any
dependence, and start taking kava only after you have discontinued the pharmaceutical.
Responsible Consumption/Use
Many people who already take medication are self-treating with herbs and not
telling their doctors. Doctors and consumers alike need to have better access to accurate
information about herbal products, regarding both beneficial and adverse effects and
drug-herb interactions. Once they become educated in this field, pharmacists can be an
excel
lent resource for this information. In the meantime, individuals should use great caution
in taking any natural product, particularly psychoactive herbs, when taking prescription
medications.
Mixing Kava and Alcohol
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Before the arrival of Europeans,
alcohol was unknown in the islands of the Pacific Ocean.. White settlers started
experimenting with combining kava and alcohol shortly after first contact. To our
knowledge, there have been two studies on the combination of alcohol and kava, resulting
in two different findings.
When mice were given an oral dose of kava followed by an injection of alcohol, the
substances greatly increased each other's sedative action.2 Human testing,
however, showed that kava tends to actually counter some of the safety-related adverse
effects of mild alcohol consumption.
Why these apparently conflicting results? The answer likely lies in the relative dose of
alcohol; the mice received far higher doses than the humans. Regardless, it appears that a
social drinker of kava or ethanol could experience increased intoxication by mixing the
two, a fact recognized by many Pacific cultures, which place cultural taboos on mixing the
two. We'll give the last word on the subject to nineteenth century explorer William
Christian, who observed "If a white trader insists on mixing good kava with bad gin,
he has simply to face the consequences. Beer, whiskey, and wine are strictly to be avoided
as incompatible with the true kava frame of mind.3
Kava and Driving
In a study of 40 healthy subjects, a standardized dose of kava did not impair
their ability to drive or to operate machinery.4
Despite this positive finding,
caution is recommended regarding driving and kava use, since in higher doses and in more
sensitive individuals it can have a sedating effect. See also the Commission E warning.
Reports of Serious Effects
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Initial media reports and a press
release by the Los Angeles Police Department implicated kava as the "problem"
ingredient responsible for the hospitalization of more than 50 young people following a
New Year's Eve "rave" concert in 1997. Labels on a product called "fX
Rush," which was given free to concert-goers as a marketing promotion, listed kava as
the primary ingredient. The victims' symptoms of dizziness, nausea, shortness of breath,
and respiratory arrest, however, are certainly not associated with the mild effects of
kava. Subsequent analysis of vials of the product confiscated by the police showed that it
contained no kava at all and did contain a toxic chemical. We assume the promoters felt
"kava kava" was exotic and unknown enough to attract the interest of the
partygoers.
This demonstrates the need for clear and accurate public information regarding
emerging herbal products. Also, it is important to be aware of unscrupulous promoters who
will make false claims for so-called mind-altering products. Some may even add kava to
other products to produce dangerous compounds.
In light of the above story, let us offer a note of caution that holds true with regard to
all substances. It is critically important to know to the best of your ability precisely
what you are taking, what its effects are, and any potentially dangerous interactions with
other substances. In addition, you should know the source of the products you are
consuming and be confident that they have not been tampered with.
No one is known to have ever died of kava overdose, compared to thousands of deaths by
drug overdose-some accidental and others suicides. Additionally, there are many deaths in
accidents caused while driving under the influence of benzodiazepines.
Animal studies give kava a wide margin of safety, with the "lethal dose
50," or LD 50-the amount required to kill half the mice-about 1,000 mg/kg.5
In studies where dogs and rats were given extremely high doses over a six-month period,
the animals showed excellent tolerance to the extract, with only mild kidney and liver
damage, and no damage to the fetus in pregnant animals.6
References
1. Almeida,J.C., Grimsley, E.W., "Coma
from the Health Food Store: Interaction Between Kava Andalprazolam" Ann Intern Med
(1996): 125: 940-941.
2. Jamieson, D.D. et al., "Positive Interaction of Ethanol and Kava Resin in
Mice" Clin and Exp Pharm and Phys (1990): 17: 509-514.
3. Smith et al., "High-Performance Liquid Chromatography of Kava Lactones"
Journal of Chromatography (1984): 283: 303-308.
4. Herberg, K.W., "Effect of Kava Special Extract WS 1490 Combined with Ethyl Alcohol
on Safety Relevant Performance Parameters" Blutalkahol (1993): 30: 96-105.
5. Meyer, HJ., eds. Efron, D.H., Holmstead, B., Kline, N.S., Pharmacology of Kava in
Ethnopharmacologic Search for Psychoactive Drugs. New York, NY: Raven Press, (1979):133.
6. Hansel, Keller, Schneider, Pharmaceutical Handbook. Verlag: Springer, (1994): 210-221.
7. See note 6 above
8. Hoffmann, R. and Winter, U., "Therapeutic Observation with a Standardized Kava
Extract" V. Phytotherapiekongress; Bonn. (November 1993).
9. Schulz, V., Hansel, R., Tyler, V, Rational Phytotherapy. New York, NY. Springer (1997):
71.
10. Gruenwald, J., Presentation at International Conference, 1996.
11. Russell, P., Bakker, D., Singh, N., "The Effects of Kava on Alerting and Speed of
Access of Information form of Long Term Memory. Bulletin of the Psychonomic Society
(1987): 25.
12. VoIz, H.P. et al., "Kava-Kava Extract WS 1490 Versus Placebo in Anxiety
Disorders-a Randomized Placebo-Controlled 25-Week Outpatient Trial"
Pharmacopsychiatry (1997): 30 (1): 1-5.
13. Volz, H.P., Interview in Clinical Pearls News (July 1997).
14. Kinzler E., Kromer, J., Lehmann, E., "Effect of a Special Kava Extract in
Patients with Anxiety, Tension, and Excitation States of Non-Psychotic Genesis. Double
Blind Study with Placebos Over 4 Weeks" Arzneimittelforschung (1991): 41 (6):
584-588.
15. Lehmann, E. et al., "Efficacy of a Special Kava Extract in Patients with States
of Anxiety, Tension, and Excitedness of Non-Mental Origin-A Double Blind Placebo
Controlled Study of Four Weeks of Treatment" Phytomedicine (1996): 113-119.
16. Norton, S.A., Ruze, P., "Kava Dermopathy" J Am Acad Dermatol (1994): 31:
89-97.
17. Shulgin, A., "The Narcotic Pepper-The Chemistry and Pharmacology of Piper
Methysticum and Related Species" Bulletin on Narcotics (April-June 1973) 25: (2):
59-74.
18. Lebot, Vincent, Merlin, Mark, and Lindstrom, Lamont, Kava: The Pacific ,Elixir.
Rochester, VT: Healing Arts Press, (1997).
19. Pfeiffer, et al., "Effects of Kava in Normal Subjects and Patients" Efron
Op. Cit. (1967):155-161.
20. Garner, L.F., Klinger, J.D., "Some Visual Effects Caused by the Beverage
Kava" Journal of Ethnopharmacology (July 1985): 13 (3): 307-311.
21. See note 13 above.
22. See note 14 above.
23. Warnecke G., "Psychosomatic Dysfunctions in the Female Climacteric: Clinical
Effectiveness and Tolerance of Kava Extract WS 1490" Fortschr Med (1991): 109 (4):
119-122.
24. Duffield, P.H., Jamieson, D., School of Physiology and Pharmacology, University of
NSW, Kensington, Australia, "Development of Tolerance to Kava in Mice" Clinical
and Experimental Pharmacology and Physiology (1991): 18: 571-578.
25. William Gunn, The Gospel of Futuna. London: Hodder & Stoughton, (1914).
26. Mathews, J.D., Riley, M.D., Fejo, L. et al., "Effects of a Heavy Usage of Kava on
Physical Health: Summary of a Pilot Survey in an Aboriginal Community." Med J Aust
(1988): 148: 548-555.
27. Singh and Blumenthal, "Kava Monograph" American Botanical Council (1997)
39:33-37.
28. Schelosky, L., Raffauf, C.,jendroska, R, Poewe, W., of the neurology department at
Rudolf Virehote University in Berlin, "Letter to the Editor" J Neural Neurosurg
Psychiatry (1995): 45: 639-640. |
