[afro-nets] Plan to stop the evolution of resistance to a new malaria drug

[Lauren Pincus <lauren@healthnet.org>]

A plan to stop the evolution of resistance to a new malaria drug
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Jan 19th 2006 from The Economist

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http://www.economist.com/background/displayBackground.cfm?story_id=5407637

There is no better example of natural selection in action than
the evolution of drug resistance. As night follows day, drugs
against infectious micro-organisms are developed, made available
to doctors, deployed successfully for a few years, and then be-
come less and less effective as genes for resistance spread
through the enemy population. This time, though, it will be dif-
ferent - at least, if the World Health Organisation has its way.

The WHO's particular concern is artemesinin, a newish drug
against malaria that cures 95% of those who take it. Arata Ko-
chi, the recently appointed head of the WHO's malaria depart-
ment, would like to keep things that way.

Dr Kochi's fear is that too much artemesinin is being taken by
itself as a so-called monotherapy, rather than in combination
with other drugs. That matters for two reasons. First, punching
a bug with two drugs simultaneously produces a bigger effect. In
combination with something else, artemesinin cures in about
three days; alone, it takes seven. The second reason is that if
a drug is administered by itself, the bug can evolve resistance
more easily. Two drugs mean that mutations protective against
both have to happen simultaneously for a resistant strain to
emerge.

Unfortunately, when drugs are combined into a single pill, the
mixture has to be approved by the authorities, with all the time
and expense of clinical trials that involves. Only one such com-
bination has been given the go-ahead so far. In the interim, the
WHO wants drug companies to "co-blister" pills made of suitable
drugs into a single pack. Not all firms are keen, though. Mono-
therapies are cheaper to make, particularly as they often come
as five-day courses rather than the seven needed for maximum ef-
ficacy. Also, sufferers who have heard that artemesinin is a
wonder drug may not understand the need for combination thera-
pies.

The WHO has persuaded many poor-country governments that their
health services should use only combination therapies, but that
does not normally apply to commercial sales from pharmacies, so
the agency has just published a list naming and shaming firms
(mostly Chinese) that sell monotherapies. Whether its lofty dis-
approval will persuade manufacturers to change their ways re-
mains to be seen. But if it does not, artemesinin risks going
the way of its predecessors.

--
Lauren Pincus
Information Officer
SATELLIFE
30 California Street, Watertown MA 02472, USA
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mailto:lauren@healthnet.org