Institute for Drugs and Medical Devices banned its use in that country.^11
Other countries followed Germany’s lead, with the result that kava-
containing products (which were commercially available as ‘food supple-
ments’) were banned from sale in Australia, Canada, Switzerland and the
UK. Regulatory authorities in other countries were less confident of a link
between kava and liver disorders. New Zealand, for example, accepted the
advice of its expert advisers and did not withdraw kava from general sale.^13
More recently the Food and Drug Administration (FDA) in the USA
has questioned the original concerns regarding the hepatotoxicity of the
product after a number of investigative studies carried out in the USA and
elsewhere. Although the debate has not yet ended, the picture that is
emerging is of a twofold problem with kava’s non-traditional compared
with traditional use. Kava use in Pacific countries such as Fiji generally
follows well-established procedures in which the root of the plant is
powdered and extracted with water and the resulting beverage drunk.^14 No
other potentially active substances would normally be consumed concur-
rently. The kava products used in non-traditional societies were often
prepared from the leaves and stem peelings of the kava plant,^13 and the
resulting extracts ingested by people who might also be using other medi-
cines that were themselves potentially hepatotoxic. The potential for kava
to interact with other medicines, especially those that inhibit the cytochrome
CYP450 system, has consequently attracted a great deal of attention.^15
The experimental studies cited by the FDA include analyses of the chem-
ical constituents of extracts prepared from different parts of the plant and
in vivo studies of the pharmacological effect of such extracts. The sedative
activity of kava appears to be related to its kavalactones, most of which are
concentrated in its roots. The hepatotoxicity that has been demonstrated is
confined to extracts prepared from the leaves and stem peelings of the
plants, which contain the alkaloid, pipermethystine.^16 This alkaloid is not
found in root extract.
The whole episode is a cautionary tale of what can go wrong when tradi-
tional usage of a medicinally active plant is extrapolated (and exploited)
beyond its boundaries by people who are unaware that, although some infor-
mation may not be written down, the way in which certain products are used
has not been arrived at by chance but by long-established observation and
experience.
Samoa
The practice of medicine in Samoa, similar to that in the other countries
discussed in this chapter, appears to have been little documented before the
arrival of the European settlers in the nineteenth century. There were no
written records from before that time and what was recorded by the very
282 | Traditional medicine