News

A herbal tea made from a homegrown plant may help beat back the scourge of malaria in Africa, where many lack access to costly prescription drugs.

Research shows Artemisia annua contains powerful compounds that can kill the malaria parasite. In fact, an anti-malarial drug, artemisinin, is derived from the plant, which originally comes from northern China.

"People need to be able to grow their own remedies, so that they have something that is readily available," said Tony Simons, a tree scientist at the International Centre for Research in Agroforesty, based in Nairobi.

Scientists, with partial funding from the Canadian International Development Agency, are trying to develop varieties of Artemisia that can thrive in sub-Saharan Africa. Some plants are already showing promise. A tea made from one particular hybrid can "kill off" all the malaria parasites in an infected person within five days, Dr. Simons said in a telephone interview. "It contains a very unusual chemical . . . that shoots an electron through the cell membrane."

What's more, there is less risk malaria will develop resistance to the tea, which contains many different compounds, compared with a purified drug composed of a single active ingredient.

Still, there are limitations to the herbal remedy. The plant's potency drops during part of the growing season, especially when it flowers.

Dr. Simons said "no single approach" will defeat malaria, which claims more than one million lives each year worldwide. He added that other medicinal plants could help treat the deadly disease, which is spread through the bite of an infected mosquito.Freedom to make mistakes

Pharmaceutical firms go to great expense to get drugs approved for treating very specific conditions. But once a drug is on the market, doctors are free to prescribe it for whatever condition they want. The practice, known as "off-label prescribing," gives physicians a lot of flexibly in treating patients. Numerous drugs are found to be effective for a variety of ailments beyond those for which they are first used.

However, a disturbing U.S. study found that many doctors are prescribing drugs in the absence of sound scientific evidence.

By reviewing the records of 3,500 doctors, the researchers found that 21 per cent of prescriptions were for off-label uses. And of these off-label prescriptions, 73 per cent "lacked scientific support," according to the study in Archives of Internal Medicines.

"Physicians may learn about off-label uses through research studies that present promising data on the benefit of a drug for off-label use. Frequently, this type of study, however, does not meet the usual standard for adequate evidence," Randall Stafford, one of the researchers at Stanford University in California, said in an e-mail interview.

For example, the study found that gabapentin, an anti-seizure drug, was widely prescribed for chronic pain. There was some evidence showing it could ease the pain from a shingles outbreak, but there was no reason to believe the drug also worked on other pain conditions.

Although the study is based on American doctors, the same trend is likely happening in Canada. Dr. Stafford said government regulators and pharmaceutical companies need to do a better job of monitoring off-label prescribing.

Asthma setback

New research has dashed hopes that early treatment of asthma can prevent it from becoming a chronic condition.

Inhaled corticosteroids are routinely used to reduce the breathing problems of people with asthma. Some doctors have speculated that these powerful medications could be used to "stop asthma in its tracks" in young children while their lungs are still developing. In particular, the drugs might be able to prevent the reduction in "lung capacity," which partly results from repeated asthma attacks.

So two major studies were set up to test the prevention theory in young children deemed at high risk of getting asthma. Some children were regularly treated with inhaled steroids, while others received placebos. Unfortunately, the results of the studies, published this week in the New England Journal of Medicine, are disappointing. "Inhaled corticosteroids did not alter the natural course of the disease," researcher Theresa Guilbert at the University of Arizona, said in a statement released with the studies.

Class action

Drug giant Bristol-Myers Squibb is facing more troubles with one of its medications. A week ago, the company disclosed that it was pulling the antibiotic gatifloxacin (sold under the brand name Tequin) from the market. The company said it made the decision "following an evaluation of the commercial potential of this antibiotic." Studies have linked the drug to dangerous changes in blood-sugar levels of some patients.

Now, a class-action law suit has been filed on behalf of Canadian patients. Charles Wright, a lawyer representing the plaintiffs, alleged in an interview with CTV News that the drug should have been pulled from the market much sooner.