and after doses as low as 1–5 mg, reported at
an incidence rate of more than 100 cases per year
to the US Food and Drug Administration (US
FDA). During general anesthesia, unexpected
hypertensive problems occur due to supra-additive
interactions. Renal stones have been reported to be
associated with ephedra use in one or two case
reports, although a causal relationship must be
viewed, at present, as uncertain. It would be illo-
gical to recommend ephedra to patients with glau-
coma, diabetes, hyperthyroidism and any other
condition that would usually cause contraindica-
tion of sympathomimetic agonists. In the United
States, the collapse of a professional sportsman
on a televised field, as well as some injuries
and deaths among military recruits during training
led to governmental concern about ephedra-
containing products. After the usual period of
public comment (which was overwhelmingly
supportive when from medical and scientific
organizations), in 2004 the FDA implemented a
ban on nonprescription ephedra-containing pro-
ducts. At the time of writing, the manufacturers
and distributors of these products are pursuing
legal avenues to reverse this regulatory action.
Ginsengis an extract ofPanax schinseng(China)
orP. quinquefolius(North America). It is a five-
leaved herb with red berries. The part used for
making complementary therapies is the aromatic
root. Ginseng is recommended for holistic mea-
sures of good health, usually stated, at their most
specific, as enhancing resistance to stress and
improving sexual function. There are one or two
case reports that ginseng can antagonize the effects
of warfarin, but otherwise this herbal medicine
does not have a reputation for intolerability.
Ginseng is more widely used in North America
and the Far East than in Europe.
Kavais an Australasian shrubby pepper (Piper
methysticum). Amidst much ceremony, its crushed
roots are made into an intoxicating beverage by the
aboriginal people of the Molucca Islands and the
Northern coast of Australia. In the west, kava is
usually recommended for anxiety; it appears to
have sedative and extrapyramidal effects, in com-
mon with some anticholinergic and antidopaminer-
gic drugs. Its sedative effects are synergistic when
administered with benzodiazepines, barbiturates
(barbitals), alcohol and some antiepileptic and
antipsychotic drugs. Kava makes Parkinsonism
worse, and can cause drug rash, photosensitivity
and itching.
Other complementary medicines:There are many
thousands of other complementary medicines.
These range from large doses of vitamins or miner-
als to extracts of many other plants and animals.
Most are not characterized toxicologically or phar-
macologically; the properties of the simplest may
be anticipated with a good clinical biochemistry
textbook at hand.
In Hong Kong, limited regulatory control of
many traditional medicines has been found to be
necessary due to their toxic nature. These regula-
tions extend over root extracts from severalAconi-
tum spp.(containing C 19 terpionoid sodium channel
blocking drugs), various herbs containing anticho-
linergic substances, toad venoms (which contain
Na–K ATPase inhibiting bufotoxins) and prepara-
tions from the more familiar genusesImpatiens,
RhododendronandEuphorbia(Tomlinsonet al.,
2000). The view through the window of a Chinese
pharmacy, in the ‘Chinatown’ of any city in Asia,
Europe or the United States, may cause different
emotions in the pharmaceutical physician and phar-
macologist. Although both may feel daunted, the
true pharmacologist also beholds an almost inex-
haustible new supply of drug development leads!30.3 Adverse effects due to
complementary therapiesIt should be noted that almost all fundamentaltypes
of adverse event have been described, including
those mentioned above. These include agonist–
antagonist interaction, protein-binding competi-
tion, metabolic adaptation and pharmacodynamic
synergy.
The general public seems to have a preconceived
notion that drugs with ‘natural’ origins, or those
which may be bought without prescription, are aut-
omatically safe. This notion is often accompanied
by an uncritical assumption that there is no need to
rigorously prove efficacya priori, and that, as ind-
ividuals, people can find out ‘if it works for them’.30.3 ADVERSE EFFECTS DUE TO COMPLEMENTARY THERAPIES 391