Danger of resistance to malaria drug

Jan 22 2006

The World Health Organization (WHO) has issued new guidelines concerning the use of the malaria drug Artemisinin.

Amid rising concern that the mosquito bourne disease is showing resistance to the drug in some areas, the WHO is asking pharmaceutical companies to curtail the marketing and sale of "single-drug" Artemisinin malaria medicines.

They believe the use of single-drug Artemisinin treatment, or "monotherapy," encourages resistance by weakening but not killing the parasite, and say it is critical that Artemisinins be used correctly.

The WHO says that when it is used correctly in combination with other anti-malarial drugs in Artemisinin Combination Therapies (ACTs), Artemisinin is close to 95 percent effective in curing malaria and the parasite is highly unlikely to become drug-resistant.

Malaria is caused by a one-celled parasite carried by mosquitoes and according to the WHO it is responsible for as many as a million deaths each year and makes another 300 million people seriously ill.

The majority of those deaths are mostly among young children in Africa.

The new treatment guidelines say that malaria must be treated with ACTs and not by Artemisinin alone or any other monotherapy.

According to the WHO although there have as yet been no documented cases of treatment failures due to Artemisinin drug resistance, the situation needs close monitoring.

They are apparently concerned about decreased sensitivity to the drug in Southeast Asia, which is the traditional birthplace of anti-malarial drug resistance.

The drug sulfadoxine-pyrimethamine which was initially almost 100 percent effective in curing malaria when introduced in 1977, was within five years only effective in 10 percent of cases due to drug resistance.

The once very popular drug chloroquine also has lost its effectiveness in almost every part of the world and resistance to atovaquone developed within one year of introduction in 1997, says the WHO.

The U.N. health agency is urging malaria researchers and the pharmaceutical industry to speed up investment and development in the next generation of antimalarial drugs.

If ACTs also become ineffective the WHO says there will then be no cure for malaria.