Adverse drug events are a serious public health problem. Consider the following facts:

• an estimated 82% of American adults take at least one medication and 29% take five or more;
• 700,000 emergency department visits and 120,000 hospitalizations are due to adverse drug events annually;
• $3.5 billion is spent on extra medical costs of adverse drug events annually;
• at least 40% of costs associated with adverse drug events occurring outside hospitals can be prevented.

How can genomics help? Pharmacogenomics is the study of genetic variation as a factor in drug response, affecting both safety and effectiveness. The intended applications of pharmacogenomics research include identifying responders and non-responders to medications, avoiding adverse events, optimizing drug dose and avoiding unnecessary healthcare costs.  The Food and Drug Administration has added pharmacogenomic information to the labeling for more than 70 drugs. Labels may include information on genetic determinants of clinical response or risk for adverse events.