/ 28 November 2006

Study finds key malaria drug well absorbed rectally

Researchers have found that artemisinin, the main drug used in fighting malaria, is well absorbed rectally, giving a promising treatment to people suffering severe forms of the disease.

Malaria can cause vomiting, which makes oral administration of the drug difficult. Facilities in rural regions are often lacking the proper equipment to administer the drug intravenously.

In a study covering Bangkok and Mae-Sot in Thailand, Ghana, Malawi and South Africa, the researchers found that the drug was sufficiently absorbed rectally by nearly all 178 patients.

Except for one person who died, everyone recovered and had the parasite cleared from their bodies, the researchers wrote in an article published in the open-access journal, PLoS Medicine.

”The reassuring thing that the clinicians found was that it was well absorbed or absorbed enough at levels that … [were] enough to clear the parasite,” Julie Simpson of the University of Melbourne told Reuters.

Malaria is one of the world’s oldest diseases and infects between 300-million and 500-million people each year, killing up to three million of them, or one person every 30 seconds.

It is caused by protozoan parasites, which thrive in humans and are passed person to person by female Anopheles mosquitoes.

There is no vaccine against the parasite, which has grown resistant to a number of well-known anti-malarial drugs, including chloroquine and pyrimethamine.

Artemisinin, a compound extracted from a Chinese herb, is regarded by medical experts as the best drug against malaria, and the WHO recommended in 2001 that it be used in combination with other drugs to slow down any development of resistance.

Although doctors administer artemisinin rectally to people who are severely ill, it is important to continue monitoring its effectiveness and the dosage used to ensure optimal therapies.

”In the malaria world now, the only really effective treatments are these artemisinin-derivatives. It would be very worrying if we found that people were not absorbing or getting [enough of] the drug … to kill the parasite,” she said.

Patients in the study were given a single dose of artemisinin, or 10 milligrams for every kilogram of body weight, a dosage which the researchers found to be sufficient.

”At the moment we don’t need to worry about altering the dose … this 10 milligram per kilogram is proving to be quite effective,” said Simpson. – Reuters