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From:
HumphreySI <[log in to unmask]>
Reply To:
Lactation Information and Discussion <[log in to unmask]>
Date:
Wed, 20 May 1998 22:08:34 EDT
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Will attempt to communicate a preliminary summary of kava - based on a quick
perusal ( it's really late to be doing this...) of the scientific studies of
kava - most herb texts do not address kava - this info from articles from the
Herb Research Foundation.

Except this: Ethnobotanical descriptions of kava ('awa) use in Hawaii relate
that pregnant women stopped taking kava for social or medicinal purposes, to
avoid miscarriage, but that breastfeeding women were not apparently
restricted.  In Hawaii, kava leaf was stuffed in the vagina to induce
abortion.

Kava, or kava-kava is Piper methysticum - a close relative of black pepper but
not of betal nut ( betal leaf is Piper but not the addictive nasty betal nut -
that's a type of palm).  Used in Polynesia for ceremonial/social, convivial
as well as medicinal purposes, to summarize somewhat inadequately.

In Germany, something like 500,000 doses were prescribed ( sorry, don't know
which year) - widely used to allay anxiety, and muscle tension states.  No
info on European use with children or lactating women.  No studies, no adverse
effects available here, folks.  Anyone in Europe know if pregnant or lactating
women with anxiety states given kava?  German Commission E report did
contraindicate for pregnancy and lactation.  Traditional use and pharmacology
may support pregnancy restriction but the Commission may have lumped the 2
states in their considerations.  For lactation, not sure what evidence would
absolutely contraindicate and the Commission may have decided on a simple lack
of knowledge of it's mode of action at the time of writing in the 80s.

The purported class of active constituents, kava lactones, do not directly
bind with benzodiazepine or GABA receptor sites but increase GABA A activity
indirectly through adjacent receptor sites and other sketchily understood
mechanisms.   One note about 3 clinical cases of unexpected but reversible
side effects (extrapyramidal) suggested dopamine antagonism.

Although animal studies noted the sedative effects of kava, with humans there
is an apparent promotion of sleep in the absence of sedation ( higher doses
may sedate ). A characteristic effect of kava lactones is skeletal muscle
relaxation, as well as smooth muscle relaxation.  High doses may cause
reversible ataxia or even paralysis without loss of conciousness.  Anti-
convulsant effects, local anesthetic, analgesic, antidepressant/mild euphoric
effects also noted in literature.

Toxicology:  LD50 oral - isolated kava lactones - 920 mg/kg for dihydrokavain
or 1050 mg/kg for dihydromethysticin for mice ( caffeine is 200 mg/kg).  Doses
of 50 mg/kg of dihydromethysticin given 3X/week for 3 months showed no
evidence for toxicity.

Several double-blind placebo controlled studies of kava have been published.
Cognitive performance, emotional stability measures improved without sedation
or side effects in one study.  Measures of heavy machinery operation showed no
significant change at the test dose, at least.  A double-blind crossover study
with oxazepam vs a standardized kava extract showed that while the oxazepam
reduced the quality/speed of responses in psychomimetic, memory and word
recognition tests, kava did not but was judged equally effective with anxiety.
A study combining alcohol showed no change in safety-related behaviors (
actually a non-significant improvement ).  Clinical trials show improved
anxiety-related symptoms without adverse effects.  Anecdotal case study ( n=1)
showed reduced visual accomodation and convergence as well as an increase in
pupil size after a fairly large dose of Fijian kava beverage was given.

Long term high dose use of kava can cause a reversible skin lesion syndrome.
A study showed that doses of 300-800 mg./day of dihyroxymethysticin would
produce this scaly skin.  In Aborigine populations in Australia, where kava
abuse has replaced alcohol abuse in some communities, this syndrome appears in
users taking in excess of 310 grams/week - a high dose.  This side effect has
not appeared in studies where 210 mg daily dose of kava lactones was
administered for 8 weeks.  Potentiation of kava lactones with alcohol,
barbituates, antidepressants or sedatives is possible.

Dose - for anxiety have seen listed as 100-200 mg. of kava lactones/day
divided dose; or hypnotic effect, taken as a single bedtime dose.  Obviously
using a product with the kava lactone content listed on label first step to
take here.  Various teas and combination products available contain smaller
amounts of kava lactones.  A bowl of kava, the traditional form of
consumption, contains about 250 mg of kava lactones.  Several bowls may be
consumed with one sitting.

This info is nicely summarized in a review by Kerry Bone. Kava: A Safe Herbal
Treatment for Anxiety. Townsend Letter for Doctors. June 1995. p. 84-87.

Dislike the title but does lead one to wonder what is a safe
anxiolytic/hypnotic for breastfeeding mothers, and safe compared to what????

Can generally provide details and refs for articles alluded to in this wordy
piece.

Sheila Humphrey  BSc(Botany)  RN  IBCLC
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