Jonathan Kahn,

Columbia University Press, 328 pages, $35

On June 23, 2005, American medicine managed to take a small step forward and a giant step backward at precisely the same time, with government approval of the first medication to be earmarked for a specific racial group. It was BiDil, a drug designed to treat heart failure in blacks.

As Jonathan Kahn writes in "Race in a Bottle," several observations prompted the drug's development. Among them was the common assertion from the last century that blacks with heart failure were more likely to die than whites. Then there was the belief that blacks often reacted badly to some of the newer drugs used for heart failure, and the results of a study dating from the 1980s suggesting that many black patients did well with two old standby drugs.

Those two drugs were (and are) on sale as generics, costing pennies a pill. But just suppose they were combined into a single pill that could be specifically marketed to patients who just happened to be thought in particular need of effective medication? Now there was a pharmacologic and marketing plan that would extend a lucrative new patent for decades.

And so it came to pass that a collection of eager investors and some of the nation's foremost cardiologists smiled on the results of an industry-sponsored trial performed on self-identified black subjects with heart failure: The two cheap drugs combined into the not-so-cheap BiDil reduced mortality by 40 percent compared with placebo.

How did whites do on BiDil? Nobody bothered to check.

Kahn deserves credit for teasing out all the daunting complexities behind these events, including the details of genetic analysis, the perils of racial determinations and the minutiae of patent law. Unfortunately, though, he suffocates his powerful subject in a dry, repetitive, ponderous read.

The issues raised are so important and so thought-provoking that it would be irresponsible to warn interested readers away. Still, it would be almost as irresponsible to misrepresent the difficulty of the journey.