Scientists have developed the world's first "race-specific" medicine for treating heart failure, rekindling a controversy over whether black people are genetically different from whites.

According to the manufacturer, drug BiDil has proved to be three times more effective in black patients than their white counterparts, the Scottish daily The Scotsman reported. 

Due to go before the United States Food and Drug Administration (FDA) for approval next week, BiDil is further proof that skin colour is a factor in the human genetic make-up, said pharmaceutical company NitroMed.
 
The firm wants to market the product for use only by black people. If approved by the FDA, it would be the first drug ever to be licensed for use by a single ethnic group.
 
"There has been a lot of controversy, but we know we have to take ethnic origin into account," Manuel Worcel, NitroMed's chief medical officer, told New Scientist magazine. "Heart failure is a catastrophe. This is a huge progress."
 
But others say NitroMed's argument could be based more on commercial considerations than hard science, and the reasons given for its efficacy in black patients might be misleading.

"You can't just say, 'We're saving people by using race' and imply races are genetically different when they're really not," said Jonathan Kahn, a bio-ethicist at Hamline University, Minnesota.

During clinical trials, BiDil improved survival rates among black people who had suffered heart failure by 47 percent. In white patients, the figure was only 15 percent.

BiDil works by boosting the level of nitrous oxide in the walls of the body's arteries and capillaries, allowing them to expand and thereby reducing the body's blood pressure. This reduces overall strain on the heart.

Kahn, while welcoming any drug that can increase patient survival, felt that the focus on race was "unfortunate and dangerous".

"When you start talking about races being genetically different, it can distract us from seeing these very real health inequalities," he said.

Yet, there is a powerful lobby in favour of racial profiling when it comes to drug development, backed by evidence that suggests a degree of truth in the ethnicity theory.

A study led by Juan Celedón at Brigham and Women's Hospital in Boston, Massachusetts, last year concluded that Puerto Rican children with asthma were up to three times more likely to have reactions to certain allergens than white children with the same condition.

At the University of Texas Southwestern Medical Centre in Dallas, a study has shown that cases of increased heart weight - an abnormality that can cause heart attacks, heart failure and stroke - were up to three times more prevalent among African Americans than whites.