Hello Ron,
In order to keep everyone happy, I will nevertheless throw in a couple
of URLs as background to this response despite your instructions to
the contrary, although my answer is based primarily on my own
understanding of the issue. I hope this does not annoy you too much :
)
Ephedra is the name of a genus of plants. The one that is most
relevant to the current issue is Ephedra sinica, from which the
traditional Chinese remedy Ma Huang is derived. Related Ephedra
plants are E. trifurca, E. viridis, E. torreyana, E. nevadensis and E.
californica ? there is a picture at
http://www.desertusa.com/april97/du_mormontea.html (web site of Desert
USA)
These are communally known under a variety of names, including ?Mormon
Tea? and ?Squaw Tea? and have been used medicinally in a number of
traditional cultures. Ephedra sinica is especially prized because it
contains high levels of the active component.
The active component in Ephedra is ephedrine. This is an alkaloid
with the chemical formula C10H15NO. The chemical structure of
ephedrine is very similar to that of adrenaline ? you can view the two
structures here:
http://physchem.ox.ac.uk/~jps/JPS-res-NT.html (web site of Oxford
University Department of Physical and Theoretical Chemistry).
Not surprisingly, therefore, the pharmacological effect of ephedrine
is very similar to that of adrenaline.
Adrenaline is often called the ?fight or flight? hormone. It kicks
into action when we find ourselves in situations of potential danger,
increasing our capacity to deal with the danger or to run away from
it. It makes the heart pump faster, thus forcing blood around the
body with greater force to supply the muscles with more oxygen, so
that they can make a greater effort. It increases metabolism, to
supply more energy to the body. It also relaxes and dilates the
airways so that we can get more oxygen into ourselves. This can be
highly useful to a Stone-Age human who suddenly comes across a
sabre-tooth tiger, and has either to kill it or run away in order to
avoid being eaten. However, an adrenaline burst that is not followed
by physical activity can be harmful to the body, inducing the
collection of symptoms that make up the syndrome of stress. One of
the most negative effects is to cause a sudden rise in blood pressure.
Ephedrine will have the same effects. That is why people sometimes
feel jittery after taking an ephedrine preparation. Often, it is
combined with caffeine, because caffeine increases the effect of
ephedrine, and thus also the jitters that are felt. The traditional
medical uses of plants containing ephedrine were as a heart stimulant,
in asthma (because it opens up the airways, much in the same way as
salbutamol - Ventolin), and also to help with allergies and hay
fever, because it helps with runny noses, itchy eyes and other such
symptoms. Ephedrine can also be used with or without caffeine, kola
or other stimulants in order to stay awake for longer than would
otherwise be possible, and it was presumably used in this way by
warriors and shamans in traditional societies. Because it gives an
energy boost, it started to be used in weight training programs.
Also, because it increases metabolism, it started to be used in weight
loss preparations.
Is ephedrine effective? Certainly its pharmacology is very similar to
that of some other drugs used to treat asthma, allergies, as heart
stimulants etc. For example, this study in published in the Journal
of Clinical Pharmacology in 1991 ?Inhaled epinephrine and oral
theophylline-ephedrine in the treatment of asthma.? concluded
?Compared with inhaled metaproterenol, inhaled epinephrine followed in
15 minutes by a theophylline-ephedrine tablet had a significantly
earlier onset, longer duration of action, numerically greater peak
effect, and patient preference?
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=2019665&dopt=Abstract
However, from the description of its activity, you will appreciate
that ephedrine is actually a pretty potent drug. A doctor who wanted
to prescribed a synthetic drug of this potency for you, would first
check very carefully that there were no contra-indications for it in
your medical history, and would want to monitor its effects on you as
well. The main concern about ephedrine preparations is that they have
been readily available for purchase over the counter. Also, their use
in weight reduction has led to far more people taking ephedrine than
would otherwise be the case. While many people have taken it with no
problems, it has also caused serious reactions in others, for example,
a paper published in 2000 in the New England Journal of Medicine
states:
?We reviewed 140 reports of adverse events related to the use of
dietary supplements containing ephedra alkaloids that were submitted
to the FDA between June 1, 1997, and March 31, 1999. A standardized
rating system for assessing causation was applied to each adverse
event. RESULTS: Thirty-one percent of cases were considered to be
definitely or probably related to the use of supplements containing
ephedra alkaloids, and 31 percent were deemed to be possibly related.
Among the adverse events that were deemed definitely, probably, or
possibly related to the use of supplements containing ephedra
alkaloids, 47 percent involved cardiovascular symptoms and 18 percent
involved the central nervous system. Hypertension was the single most
frequent adverse effect (17 reports), followed by palpitations,
tachycardia [= rapid heart rate], or both (13); stroke (10); and
seizures (7). Ten events resulted in death, and 13 events produced
permanent disability, representing 26 percent of the definite,
probable, and possible cases.?
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=11117974&dopt=Abstract
Thus the adverse effects can be extremely serious and even fatal.
You also ask how many people have had serious consequences from
ephedra use. A web site of a legal company acting for people making
legal claims against suppliers of ephedra products stated in 2003:
?Since 1994 the FDA has received and investigated more than 1000
reports of adverse events associated with the use of Ephedra products.
According to the FDA, reported adverse events range from ?episodes of
high blood pressure, irregularities in heart rate, insomnia,
nervousness, tremors and headaches, to seizures, heart attacks,
strokes and death.? The FDA has commented that ?Most events occurred
in young to middle aged, otherwise healthy adults using the products
for weight control and increased energy.?
The Annals of Internal Medicine reported that, although ephedra
porducts make up less than 1 percent of dietary supplement sales, it
has accounted for 64 percent of the serious side effects that have
been reported to the Centers for Disease Control and Prevention in
association with dietary supplements.?
http://www.ephedrareport.com/about.html (Ephedra Report)
Well, 1000 or so reports is not a lot when compared with the millions
who have used these products. However, the FDA and other drug
regulatory agencies act to ensure that drug adverse effects are kept
to a minimum, and that drugs causing serious adverse effects are only
used when the clinical benefits outweigh the risks.
In the case of ephedrine, I believe that the issues are as follows:
Ephedrine is a very potent drug that can sometimes cause serious
adverse effects, and therefore it is not the best thing for people to
obtain as in an over-the-counter preparation and use for
self-medication and for non-medical purposes. This is even more
relevant considering that most adverse events have, as noted in the
comment from the FDA above, occurred in relatively young and healthy
people who were not using it for specific medical conditions.
Other drugs that do not have as great a potential to cause serious
adverse effects can be used to obtain the same benefits as obtained
with ephedrine.
Therefore, there is a case for withdrawing permission for
ephedrine-containing preparations to be available for free purchase.
However, note that the ban only applies to dietary supplements, not to
the use of ephedrine in controlled clinical situations:
?Essentially all currently marketed dietary supplements that contain a
source of ephedrine alkaloids, such as ephedra, ma huang, Sida
cordifolia, and pinellia will be affected by this rule. The rule does
not pertain to traditional Chinese herbal remedies. It generally
doesn't apply to products like herbal teas that are regulated as
conventional foods. In addition, products regulated as drugs that
contain chemically-synthesized ephedrine, are not dietary supplements
and not covered by this rule. These include drugs used for the
short-term treatment of asthma, bronchitis, and allergic reactions.?
http://nccam.nih.gov/health/alerts/ephedra/consumeradvisory.htm
(NCCAM ? National Center for Complementary and Alternative Medicine,
National Institutes of Health, Bethesda)
I think a further interesting consideration that arises is that people
act very differently when with respect to their own risk-associated
behaviour than when the risk is imposed on them by an external power.
Would the people who are disappointed by the ban on ephedra have the
same opinions if we were looking at a prescription drug with the same
level of potential toxicity?
I hope that this answers satisfies your query, but please request
further clarification if required.
Tehuti
Search strategy on Google and PubMed
( http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed )
ephedra
ephedrine efficacy
ephedrine toxicity |
