Pharmacogenomics has the potential to improve public health, writes Muin Khoury, the director of the Centers for Disease Control and Prevention's public health genomics office, at the Genomics and Health Impact Blog. About 700,000 emergency department visits each year are due to adverse drug reactions and, Khoury says, genomics, particularly pharmacogenomics could help cut down on those numbers. However, there are only a few pharmcogenomic tests being used in the clinic. "Although considerable information is accumulating on the relationship between genetic variation and drug metabolism and adverse effects, precious little evidence exists for their added value in clinical practice," he writes. Khoury adds, though, that there are initiatives underway to assess the use of pharmacogenomic tests.