|
Ephedra
Controversy
- part 2
18
September 2000
by
Wyn Snow, Managing Editor
What
is causing these adverse events?
Some
of the reports of adverse events contain details that are biologically
impossible, strongly suggesting that they are false reports, but
it's unlikely that all of them are. Given that some of these reports
probably reflect real problems, what kind of fire is causing all
this smoke?
Overdosage
One
cause of an adverse event can be "too much of a good thing" -- the
notion that if one is good, two will be better -- with a toxic reaction
as the result of an overdosage. Used in moderation or under a health
provider's direction, most supplements are quite safe. However,
some supplements (even vitamins and minerals) can be toxic at higher-than-recommended
dosages. Ephedra is one of those supplements.
B.
J. Gurley at the University of Arkansas compared the physiological
effects of three commercially available ephedra products with a
25-mg ephedrine capsule -- and found that "pharmacokinetic parameters
for botanical ephedrine were similar to those for synthetic ephedrine."
He concludes that "the increased incidence of ma huang toxicity
results from accidental overdose often prompted by exaggerated off-label
claims and a belief that 'natural' [products] are inherently safe."
Heightened
sensitivity
Also,
just as some people have allergies to various foods or a heightened
sensitivity to caffeine, it's very likely that some people react
especially strongly to ephedra. Even with pharmaceutical drugs (which
undergo extensive testing for safety), it is typical that after
a drug receives FDA approval, a small percentage of the wider population
has side-effect reactions to the drug that were not observed during
clinical trials associated with the drug-approval process.
Of
twelve people with normal blood pressure in another research study
at the University of Arkansas conducted by L. M. White, "Six participants
experienced a statistically significant increase in heart rate,
but the effects on blood pressure were variable."
Interactions
Another
plausible cause lies in interactions with prescriptive drugs or
other products. The herbal industry's guidelines for ephedra label
warnings include a statement that people using an MAO inhibitor
or any other prescription drug should consult a health care professional
before using an ephedra product..
A
case study reported by S. M. Zaacks at Chicago's Rush Presbyterian
St. Luke's Medical Center involves a man who took ma huang together
with vitamin supplements and two prescriptive drugs: pravastatin
and furosemide. The authors conclude that ephedra "is the suspected
cause of hypersensitivity myocarditis [inflammation of the heart
muscle] in this patient."
Caffeine
That
morning cup of coffee may also be a factor in ephedra-related adverse
reactions! Caffeine is an ingredient in many ephedra-based herbal
weight-loss products. Research suggests that ephedrine-plus-caffeine
can both suppress appetite and increase fat-burning. However, both
ephedra and caffeine (either singly or in combination) also have
side effects of tremors, insomnia, and dizziness.
Claimants
in approximately 75 lawsuits say that taking ephedra products has
also caused them to have cardiac arrhythmia, high blood pressure,
heart attack and stroke. Just as it is dangerous to combine alcohol
and barbiturates (two sedatives), it may be unwise to combine two
stimulants: ephedra and caffeine. Drinking tea or coffee in addition
to taking an ephedra-based weight-control product would certainly
intensify any potential dangers of such a combination!
Recent
research will soon shed new light on this question. Dr. Carol Boozer
of New York's Columbia Medical School looks forward to publishing
new results in October 2000. This 6-month research program studied
both the safety and effectiveness of ephedra-plus-caffeine in 150
randomized subjects. The first month of work focused explicitly
on safety issues, including cardiac arrhythmia's, blood pressure,
and blood composition.
Contaminants
Ma
huang is a Chinese herb, and some herbs imported from Asia have
been found to be contaminated in a variety of ways. Contamination
of L-tryptophan was responsible for the outbreak of eosinophilia
myalgia syndrome (causes muscle disease and nerve damage) that affected
thousands of people in 1989. Also, ConsumerLab's latest off-the-shelf
testing of ginseng products, another Asian herb, found that 8 of
the 21 products tested were contaminated with either pesticides,
lead, or both.
Inconsistent
potency
Finally,
ephedra products vary widely in their potency levels -- both in
labeled dosages and actual tested potency. Labeled dosages range
from 5 mg to 75 mg of ephedrine. However, one independent laboratory
analysis of nine ma huang products showed actual levels ranging
from 0 mg (none!) to 56 mg of ephedrine alkaloids. Another analysis
of 20 supplements found that half of the products "exhibited discrepancies
between the label claim for [ephedrine] and actual [ephedrine] content
in excess of 20%." Again, one product contained no ephedra alkaloids
whatsoever, and some of the brands varied from one lot to another
in how much ephedrine they contained.
Ephedra Controversy Heats Up Again
Ephedra is the main ingredient in several popular weight-loss
products . . . and has appeared in almost a thousand
reports in the FDA's database of serious adverse effects . . .
Solving these problems
One solution to the ephedra problems is . . .
|
