STEPS MUST BE TAKEN TO AVOID RESISTANCE TO LATEST MALARIA DRUG,
UN AGENCY WARNS
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New York, September 6 2005 11:00AM
The United Nations health agency today called on countries to
adopt monitoring measures to ensure that new life-saving malaria
medicines do not lose their effectiveness through misuse, pro-
ducing resistant strains of a disease that causes more than 300
million acute illnesses and 1 million deaths annually.
"It is crucial that these medicines be used correctly," said
Pascal Ringwald, a medical officer in the World Health Organiza-
tion
http://www.who.int/mediacentre/news/releases/2005/pr40/en/index.html
WHO Roll Back Malaria (RBM) Department and principal author of a
new report on global monitoring of antimalarial drugs released
today.
The report, Susceptibility of Plasmodium Falciparum to Antima-
larial Drugs, warns that as more and more people gain access to
the medicines, which combine a drug derived from the plant Ar-
temisia annua with a second, synthetic drug, it is vital that
countries closely monitor their effectiveness.
More than 50 governments have followed WHO's recommendations on
malaria treatment and adopted artemisinin-based combination
therapies (ACTs), the most effective antimalarial drugs avail-
able today. This has enhanced prospects for reducing the burden
of the disease worldwide.
Drugs derived from the plant Artemisia annua must be used as
ACTs in combination with a second drug, and not alone. Other-
wise, the medicines could lose their potency over time due to
the development of resistance. This has already happened with
other antimalarial drugs such as chloroquine, once a mainstay of
treatment.
To avoid this, WHO is calling on countries to use only WHO-
approved ACTs (an artemisinin-based drug combined with amo-
diaquine, lumefantrine, mefloquine or sulfadoxinepyrimethamine)
of high quality, since drugs of low potency can promote resis-
tance.
All people taking antimalarials should be educated about the im-
portance of finishing their medication courses, since incomplete
treatment is another cause of resistance, WHO warned. Any change
in efficacy of antimalarial drugs should prompt an appropriate
update in a country's treatment policy.
The danger of resistance stems from the malaria parasite's abil-
ity to evade the lethal action of drugs. Because malaria para-
sites are genetically highly diverse, some strains can escape
drugs unharmed and pass along their resistance to progeny. As
sensitive organisms die off, resistant strains may come to domi-
nate, and over time an antimalarial drug can lose its ability to
cure infection.
Resistance is more likely to occur when only one drug is used.
Combining an artemisinin-based medicine with another antimalar-
ial drug, as WHO recommends, sharply reduces the risk. "To date
no treatment failures due to artemisinin drug resistance have
been documented, but we are watching the situation very atten-
tively," Dr. Ringwald said.
"We have the means to enhance the lifespan of ACTs. In addition,
we must move forward energetically on research to develop new
antimalarial medicines," said Fatoumata Nafo-Traoré, Director of
WHO's RBM Department.