Subject: Side Effects/Toxicity

From: [email-masked] (Jonathan Treasure)
Date: 17 May 1995 13:53:22 +0100

INTRODUCTION TO SIDE EFFECTS, SAFETY AND TOXICITY OF MEDICINAL
HERBS.

This introduction  concerns WESTERN medical herbs and their
clinical use.  Some herbal agents are common to different
traditions but the indications and methods of use may vary
between eg TCM, Ayurvedic and Western practices.

The purpose of these notes is to provide a general  understanding
of the actions of herbal medicines, and  hence a background for
understanding questions of safety and toxicity - NOT to provide a
list of problematic herbs. A brief bibliography gives sources of
reliable information on the safety of herbal medicine and further
reading.

 ================================

Conventional medicine considers that if a drug is to be
effective, it will inevitably have side effects. The medical
establishment considers herbal medicines as drugs, and as such,
they must either have side effects - or ergo be ineffective.

Paradoxically tens of thousands of people every year turn to
herbal medicine because they regard plant remedies as being free
>from  undesirable side effects. Herbal medicines are considered to
be generally safe AND effective agents.

Although there is a spectrum of viewpoints in western herbal
medicine, most herbalists reject the view that plant medicines
are naturally occuring analogues ofthe pharmaceuticals used in
orthodox clinical medicine ie drugs.  

This is ultimately  a  rejection of the dominant paradigm of
orthodox clinical science. It is necessary to outline the
elements of the alternative paradigm shared by most herbalists, 
before questions of toxicity and safety can be discussed in
context of clinical herbal therapeutics, rather than of orthodox
medical science.

1. MEDICINAL PLANT ACTIONS CANNOT BE REDUCED TO THE EFFECTS OF
THEIR  ISOLATED ÒACTIVE  CONSTITUENTSÓ

There ARE a few plants that are almost Òdrug likeÓ and whose
action approaches that of pharmaceuticals. Digitalis is the
classic  example. Herbalists use these plants in near allopathic
treatment strategies if at all, and in some countries eg UK,
their availability is restricted  by law. The number of herbs in
this category is relatively few.

The vast majority of medicinal herbs contain dozens of different
compounds, often of great complexity,  mucilages, tannins,
polysaccharides etc that buffer, modulate and modify the effects
of any Òactive principlesÓ.  Study after study has shown that
effects produced by extracts of whole plants cannot be mimicked
by  administering  isolated purified constituents of the plant. 

(It is ironic this proposition even has to be asserted given that
biological sciences have for some time used a systems theory
model in which the whole being greater than the sum of the parts
is axiomatic - this  simply reflects the inherent conservatism of
the medical establishment. However for most herbalists  the view
of the whole being greater than the parts is derived from
vitalism, not systems theory!) 			

2. MEDICINAL HERBS ACT  ÒMULTI-SYSTEMICALLYÓ 

Pharmaceutical drugs  are designed to elicit very specific
reactions. Their  associated  Òside effectsÓ are undesired
actions, usually traded as a ÒriskÓ against the ÒbenefitÓ of the
primary effect. Herbs tend to have several broad actions on a
number of whole physiological systems at the same time. These 
actions are usually oriented in the same general therapeutic
direction, and are usually complementary or synergistic, often
non-specific, and very rarely adverse. Herb actions cannot be
adequately described using the vocabulary of ÒdrugÓ action terms.
eg diuretic etc  - they are too complex. The clearest example of
this is the coining of the term Òadaptogenic Ó used to describe
the  multiple non-specific effects of herbs such as Ginseng.

3. HERBS ACT ON THE HEALING PROCESSES IN THE  BODY.

A pharmaceutical drug addresses symptoms caused by specific 
disease mechanisms as understood by scientific pathology. Herbal
medicines are directed towards aiding the bodyÕs own healing
processes. These approaches are diametrically oppposed. Herbal
medicines act gently, usually attempting to ÒnudgeÓ  orÒsupportÓ
systems and  processes that have become deficent or help remove
excesses that have become preponderant. Symptom relief is only a
component of herbal therapeutic strategy. 

This is a crucial difference. For example, serum arthritic
conditions are conventionally treated with steroid
anti-inflammatory drugs. These have widespread and disturbing
side effects, which at sustained high doses become intolerable
and potentially dangerous if not lethal. The herbal approach to
these conditions uses dietary modification of metabolism;  
facilitation of elimination via kidneys and hepatic/biliary
routes; stimulation of circulation in the affected regions,
moistening of dry synovia,etc Topical treatments for acute joint
pain or systemic anti-inflammatory herbs that help joint pain are
used as required, but this is not the thrust of the treatment
strategy.  Lay persons often make the related mistake of seeking
a "natural alternative" to a pharmaceutical they have been
prescribed rather than challenging the diagnosis and therapeutic
strategy.   

4. HERBS ACT MULTI- DIMENSIONALLY 

Herbal medicine is a wholistic therapy, it integrates  mental,
emotional and spiritual levels seamlessly into its understanding
of both  human function and of the plant remedy, while respecting
the planetary and ecological dimensions of  natural medicine
provided by plants.  Although subject to differing
interpretations this view is held in one form or another by most
herbalists . 

Life style, mental, emotional and spiritual considerations are
part of any naturopathic approach, herbalism included. Flower
essences, homeopathic preparations and drop doses of standard
herb extracts all demonstrate that herbal agents can produce
consistent and powerful effects at subtle levels in ways quite
inexplicable by the pharmacokinetic model underlying orthodox
pharmacology. 

Centuries of medicinal plant usage overarch even the Graeco -
Roman heritage of medical thought ,itself already forgotten by
its  amnesiac infant technological medicine,  extending into
magical, esoteric and religious domains of prehistory. The great
Asian systems of medicine have continued uninterrupted for
thousands of years to today,integrated into profound cosmological
and philosophical systems. From any serious study of the
application of herbs to healing a perspective emerges that
reveals  modern doctors to be tragi-comically  Òlike educated
peasants running around pretending to be chiefsÓ (Grossinger).

5. SIDE EFFECTS  VS  CONTRAINDICATIONS

Many herbalists would tend toward the radical homeopathic view
that the Òside effectsÓ of orthodox medicine are in fact
iatrogenic developments of the very disease for which the
pharmacological intervention was intended. The symptoms simply
change, and the real underlying dysfunction is further obscured -
or driven further into the interior to manifest in deeper and
more intractable ways.

Notwithstanding this iatrogenic view of side effects, we have
seen that the use of herbs anyway does not generally involve
ÒdrugÓ actions or adverse effects. Of course, if the body
processes are nudged in the wrong direction for long enough, then
imbalances can worsen rather than improve. Hence the need for
informed  knowledge of the effects of herbs as well as a clinical
training to understand their appropriate medical application.
Herbalists learn about the  CONTRAINDICATIONS as well as the
indications for using a herb. This term is more useful and
appropriate than "side effects". 

CONTRAINDICATIONS are incongruences between the
metabolic/systemic  predisposition (constitution) of the
individual -  and the spectrum of multi-systemic actions of a
given herb agent or class of agents. Essentially , herbalists use
their in depth  knowledge to devise a mixÕnÕmatch  prescription
tailored precisely to fit an indivduals unique  profile. This
approach is most sophisticated in the tonic energetics of the
Oriental medical traditions, but is empirically applied by most
herbalists. 

Contraindicated remedies can account for aparently idiosyncratic
Òbad reactionsÓ to a herb. Valerian is a classic example, its
powerful autonomic effects can make it ÒdisagreeÓ with stressed 
adrenergically hyperactive individuals, who paradoxically are
often those seeking sedative treatment for insomnia.  Anyone
experiencing such reactions to a herb for more than a couple of
days should stop taking it and seek further advice. However a
second and vital aspect of contraindications  especially  today
is the question of  DRUG INTERACTIONS.

Many people seeking herbal medical treatment are already involved
in pharmaceutical therapies.  Herbal remedies may act either as
agonists or potentiate some drug therapies, and an understanding
of conventional drugs is an essential prerequisite for effective
herbal therapueutics.  In many cases, herbalists would not treat
the primary presenting symptom undergoing  drug treatment - be it
ulcers treated with Zantac or cardiac arrythmia treated with
Digoxin - but rather concentrate on supporting other systems and
functions stressed by the primary symptom. This allows the body
to recover its strength and healing potential so it can then
direct these capabilities  toward repairing  the presenting
condition. In other cases, it can be a priority to wean someone
off drugs, eg steroids, in which case supportive therapy to
restore adrenal function is vital. 

6. SAFETY AND TOXICITY OF HERBAL MEDICINES

The definition of *toxic* is a ultimately a matter of viewpoint.
Many ordinary foods contain constituents that could be regarded
as poisonous, such as the alpha gliadin produced by gluten in
wheat oats and rye, the cyanogenic glycosides in many fruit
seeds, the thiocyanates of the brassica vegetables , alkaloids of
the Solanaceae and lectins of many pulses including soya and red
kidney beans. Nonetheless these foods are generally regarded as
safe. Similarly, both water and oxygen - can kill in excessive 
amounts, so quantity is often an important consideration. In
practice however , three groups of herbs can be identified  from
a safety point of view.

Firstly there are a handfulcof herbs that contain near
pharmaceutical concentrations of poisonous constituents which
should on no account be taken internally by unqualified persons
except in homeopathic potencies. Examples are Atropa belladonna,
Arnica spp, Aconitum spp, Digitalis spp. In many countries
availability of these herbs is limited by law. Regulations vary
>from  country to country and the appropriate regulatory
authorities or Herb Organisations can be consulted for details.
Wildcrafters should be  unshakeably confident in their
identification of the local variants of these species, and
children warned to avoid them. Fortunately this is a numerically
tiny category. 

Secondly, are herbs with  powerful actions, often causing  nausea
or vomiting, (that usually  were traditionally prized for this
action).  They  are perfectly safe used under appropriate
conditions. Some ofthese herbs are restricted in some countries
but freely available in others. Lobelia and Eonymus spp are
examples.There is some inconsistency here, for example Ephedra is
restricted, perhaps with justification, in the UK, but is freely
available in the US. 

Finally, there is an idiosyncratic grouping of herbs which have
been alleged, with some scientific support, to exhibit specific
kinds of toxicity. The best known is the  hepatotoxicity  of
pyrrolizidine alkaloid containing plants such as Comfrey
(Symphytum).  Other examples are Dryopteris (Male Fern) , Viscum
(Mistletoe) and   Corynanthe (Yohimbe) . Although much of the
evidence is contentious ( see below), lay users would be advised
to avoid internal consumption of these herbs.

The vast majority of medical herbs are safe for consumption, but
for those without specialised knowledge, it would be prudent to
follow simple but sensible guidelines in self treatment:

- Use only herbs recommended in respected herb books, especially
in countries like the US where there are few restrictions on
availability.

- Avoid new or unproven *wonder remedies*.

- Do not persist with a remedy if no benefit or result  obtains
after a moderate period, and if adverse reactions take place,
stop the treatment and seek experienced advice. 

- Do not persist with a treatment that has brought improvement
without testing to see if continued further consumption is
necessary to maintain improvement. 

- Do not engage in self treatment for complex conditions without
experienced advice. Drug interactions and contraindications must
be considered on an individual basis and herbaltreatment
strategies are often involved and multifaceted.

Unfortunately,training and licensing of herbalists is not
internationally consistent. In the US the situation is especially
complex - no recognised herbal licensing exists. NDÕs are
licensed in a few states, but their herbal training could
theoretically be less than that of an unlicensed but experienced
herbal practitioner.  In the UK, the NIMH accredits herbalists
who have trained at approved courses: practitioners are
recognised by MNIMHor FNIMH qualifications. 

7. PREGNANCY 

It is axiomatic that pregnancy should be a time of minimal
medical intervention, and herbalists in particular regard
pregnancy as a ÒcontraindicationÓ to taking herbal medicines.
Nutritive Òfood herbsÓ such as nettle, and uterine tonics such as
raspberry leaf are encouraged, and perhaps gentle treatments
againsttypical  symptoms such as constipation or morning sickness
are in order.  There is NO evidence of teratogenicity in humans
arising from herbal remedies, but since such evidence would be
hard to come by, erring on the side of caution is regarded as
prudent. 

8. UNDERSTANDING TOXICITY RESEARCH - POLITICS AND IDEOLOGY

Medical orthodoxy at best does not understand herbal medicine,
and at worst, sees it as a threat which it attempts to rubbish,
regulate or ridicule. Quackery  has a fascinating role in the
history of medicine and its institutions, but much of the
hostility towards herbal medicine comes from its apparently
greater proximity to orthodoxy than say acupuncture  or
homeopathy. This is the unfortunate political context in which
toxicity and safety of herbal medicines are debated. 

Additionally, both professional herbalists and regulatory
authorities exhibit differing degrees of education, organisation
and aptitude in different countries. In the United States, the
situation is particularly lamentable, with scare mongering
stories regularly aired in medical, scientific and popular press,
whilst the lack of accredited professional herbalist training 
means that well intentioned self-appointed spokespersons for
herbalism can cause more harm than good, and the quixotic federal
regulatory stance on herbs as foodstuffs means that the potential
of lay self-iatrogenesis with  freely available OTC herbal
products is a serious possibility. 

Toxicty of herbal medicines needs to be seen in context however.
As Paul Bergner, Editor of the journal Medical Herbalism and
author of several articles on herbal toxicty recently pointed
out:

*Approximately 8% of all hospital admissions in the U.S. are due
to adverse reactions to synthetic drugs. That's a minimum of
2,000,000. At least 100,000 people a year die from them. That's
just in the U.S., and that's a conservative estimate.That means
at least three times as many people are killed in the U.S. by
pharmaceutical drugs as are killed by drunken drivers.  Thousands
die each year from supposedly "safe" over-the-counter remedies. 
Deaths or hospitalizations due to herbs are so rare that they're
hard to find. the U.S. National Posion Control Centers does not
even have a catagory in their data base for adverse reactions to
herbs.*

Similar figures apply in the United Kingdom, and even
hepatoxicty,  where perhaps the stongest case against some herbs
lies, the statistics are horrendously clear - over 80% of cases
of fulminant hepatic failure presenting for liver transplant (or
death) over ten years inthe UK were due to poisoning by freely
available OTC  non-prescription NSAIDÕs, such as paracetomol and
aspirin. Not one case was due to ingestion of medicinal herbs.

For the lay person, analysis of so called Òscientific evidenceÓ
about toxicity is clearly problematic. Some of the most useful
sources of information are to be found in review presentations
made by representatives of the herbalist community to regulatory
authorities such as the FDA or MCA. Informative reviews of the
literature in defence of Comfrey and Mistletoe have been made in
this way.

Herbalists justifiably point out that scientific studies with
isolated compounds, on non human or even non mammalian organisms,
or in vitro , with doses tens or even  hundreds of times the
equivalent medicinal dose, simply have no arguable extrapolation
to the clinical situation using whole herb at appropriate
medicinal doses.

 Lack of herbal knowledge knowledge by some scientific
investigators (let alone journalists or self appointed defenders
of  the public) leads to often ludicrously misleading results - 
one of the commonest mistakes being the failure to verify the
actual identity of plant material used in their experiments, let
alone the detection  of contaminants!

These points beg the question of what paradigm can be used for
research into the safety and efficacy of herbal therapies. That
shibboleth of orthodoxy - the  double blind placebo controlled
clinical trial is open to a range of criticsms from the paradigm
employed by herbalists - but that, as they say, is another story.

FURTHER READING

HERBAL /MEDICAL CONTRAINDICATIONS:
Synergistic and Iatrogenic Potentials when some herbs are used concurrent
with Medical
Treatment or Medical Health Care by Michael Moore, 1995 , on line
at  http://www.crl.com/~robbee/herbal.html

HERB INFORMATION RESOURCE:
The Information Source book of HerbalMedicine: David Hoffmann,
Crossing Press 1994. This excellent book is reviewed at 
 http://www.crl.com/~robbee/herbal.html

TOXICOLOGY:
Brinker F : An Introduction to the Toxicology of Common Botanical Medicnes,
NCNM 1983
AMA Handbook of Poisonous and Injurious Plants AMA, Chicago 1985
NAPRALERT database at UIC. 

Example REVIEWS OF PROBLEMATIC HERBS:
In Defence of Comfrey: EJHM1.1.1994 11-17 
The Case For Mistletoe EJHM1.1 1994  17-22
EJHM = European journal of Herbal Medicine

HISTORY:
 Planet Medicine - Richard Grosssinger, North Atlantic Books 1990
The Magical Staff , Matthew Wood North Atlantic Books, Berkely 1992

GENERAL HERB BOOKS:
J.A. Duke, 1985. CRC Handbook of Medicinal Herbs, CRC Press.  
C. Hobbs, (many booklets). Topics: Echinacea,
Usnea, Medicinal Mushrooms, Natural Liver Therapy, Vitex, Milk
Thistle, Immune Therapy. Botanica Press, Box 742, Capitola, CA 
95010.  (Most are $5- $10).
D. Hoffmann, 1988. The Herbal Handbook: A User's Guide to Medical
Herbalism,  Healing Arts Press.  All texts by Hoffmann are reliable.
S. Mills, 1992.  Out of the Earth: The Essential Book of Herbalism, Viking
Press.
*>M.Moore, 1979. Medicinal Plants of the Mountains West, Uof NMPress. 
*>M. Moore, 1990. Medicinal Plants of the Desert West, U of NM Press. 
*>M. Moore, 1993. Medicinal Plants of the Pacific West, Red Crane Press.
R.F. Weiss, 1988. Herbal Medicine,