Herbs for the Nervous System: Ginkgo, Kava, Valerian ... - Nutraxin

Herbal medicine 85
To varying degrees, ginkgo acts as an antioxidant, or scavenger
of free radicals, which have been considered the mediators
of the cell damage observed in brain aging, including in
Alzheimer disease. 6,10,11
Adverse effects
In a German observational study of 10,815 patients treated
with ginkgo (LI 1370), only 183 reported some mild side
effects. They included nausea, (37) headache, (24) stomach
problems, (15) diarrhea, (15) allergy, (10) anxiety/restlessness,
(8) sleep disturbances, (6) and “other” (68). 12
The toxicity of ginkgo leaf extracts is very low. In rats, even
extremely high doses were not fatal. No evidence of cancer,
or genetic mutations were found in animals treated with
ginkgo nor any birth defects in the offspring of treated pregnant
females. 12
Since ginkgo has an anticoagulant effect, it has been associated
with serious bleeding problems in rare cases, three that
have been published. These include two cases of spontaneous
subdural hematoma, subarachnoid hemorrhage and
mildly increased bleeding time, and spontaneous bleeding
from the iris, all in persons taking other medications (also
with anticoagulant effects)–coumadin, acetominophen, and
aspirin. 13,14 All recovered with no aftereffects.
Dosage
The typical dose of ginkgo is 40 to 80 mg three times daily of
a 50:1 extract standardized to contain 24% ginkgo flavone
glycosides. It may take up to 6 weeks before yielding any
results.
Warning. Ginkgo should not be used with anticoagulants,
or by patients with clotting problems, without medical
supervision.
Kava (Piper methysticum)
This psychoactive member of the pepper family has been
used historically in the South Pacific Islands as a ceremonial
and recreational tranquilizing beverage. 15,16 It is an approved
medication in Germany for “states of nervous anxiety, tension,
and agitation” in doses of 60-120 mg of kavalactones for
up to 3 months duration. 17 Rather than implying any danger
in continued use, the 3-month limit is more likely a suggestion
that one should explore other causes for the anxiety,
including those amenable to psychotherapy and stress-reduction
techniques.
Kava is increasingly popular in the United States for shortterm
relief from anxiety and stress. This includes successful
use for such stressors as fear of flying and performance anxiety.
In one example, a 28-year-old screenwriter reports that
he took kava (2 60 mg caps) successfully to overcome
presentation “nerves,” with no impairment in his ability to
concentrate and perform. 18 The muscle-relaxing effects make
it particularly useful in treating headaches, backaches, and
other tension-related pain.
Research
In clinical studies, kava has been compared favorably to both
placebo and benzodiadepines. Unlike the benzodiazepines,
however, kava is unlikely to produce tolerance, withdrawal,
addiction, or morning-after drowsiness. In lower doses, for
most people, it may even enhance rather than impair cognitive
function. 19 Following are a few of the many positive
studies on kava.
Kava vs Placebo
● In a randomized, double-blind, placebo-controlled
trial, 58 patients with diagnosed anxiety and neurotic
disorders were randomly given either 70 mg of kavalactones
(extract WS 1490-Laitan ® ) or placebo three times
daily for 4 weeks. Unlike the placebo group, the kava
group showed a significant reduction in anxiety assessed
by the Hamilton anxiety scale (HAMA) with minimal
side effects. 20
● The longest–running study with the most subjects to date
was done by Volz and Kieser 21 in 1997. A randomized,
double-blind, placebo-controlled multicenter study of 101
outpatients with DSM-IIIR anxiety disorders (agoraphobia,
specific phobia, GAD, adjustment disorder with anxiety)
were treated with the kava extract, WS1490 (210
mg/day in divided doses), for 24 weeks. The results
showed significant reductions in the HAMA in the kava
group beginning in the 8th week and increasing throughout
the trial. Improvements were also seen in somatic and
psychic anxiety, Clinical Global Impression, Self-Report
Symptom Inventory, and Adjective Mood Scale. Moreover,
there were no negative effects on clinical chemistry,
hematology, or vital signs nor did any tolerance develop.
● In a placebo-controlled trial, 58 patients with anxiety
received 210 mg kava or placebo daily for a month.
Compared to placebo, those receiving kava had significantly
greater reductions in HAMA scores starting at 1
week. 22
Comparison with Benzodiazepines
● In a comparison treatment study, a daily dose equivalent
to 210 mg of kavapyrones was compared with 15
mg/day of the benzodiazepine oxazepam or 9 mg/day
bromazepam for 6 weeks. In the 164 patients who completed
the trial, HAMA ratings did not differ significantly
among the three groups. 23
● In 12 healthy volunteers, a kava extract was compared
with oxazepam in a double-blind crossover study of
event-related potentials and recognition memory.
While oxazepam impaired both of these, kava slightly
enhanced performance. 19
Kava for Menopausal Symptoms
A study of kava for menopausal symptoms in 40 women
using doses of 30-60 mg/day for a minimum of 56 days found
significant improvements in anxiety, hot flashes, sleep, and a
sense of well-being, as well as in the HAMA scale and Kupperman
index. 24 In a follow-up study in 40 women (20 on
placebo and 20 on 210 mg/day), similar effects were reported.
25 In my clinical practice, I have found it excellent for
this purpose, as well as for treating symptoms of PMS.