From Scientific American:
Two years ago, on June 23, 2005, the U.S. Food and Drug Administration approved the first “ethnic” drug. Called BiDil (pronounced “bye-dill”), it was intended to treat congestive heart failure—the progressive weakening of the heart muscle to the point where it can no longer pump blood efficiently—in African-Americans only.
A close inspection of BiDil’s history, however, shows that the drug is ethnic in name only. First, BiDil is not a new medicine—it is merely a combination into a single pill of two generic drugs, hydralazine and isosorbide dinitrate, both of which have been used for more than a decade to treat heart failure in people of all races. Second, BiDil is not a pharmacogenomic drug. Although studies have shown that the hydralazine/isosorbide dinitrate (H/I) combination can delay hospitalization and death for patients suffering from heart failure, the underlying mechanism for the drug’s efficacy is not fully understood and has not been directly connected to any specific genes. Third, and most important, no firm evidence exists that BiDil actually works better or differently in African-Americans than in anyone else. The FDA’s approval of BiDil was based primarily on a clinical trial that enrolled only self-identified African-Americans and did not compare their health outcomes with those of other ethnic or racial groups.