Woosley's research has been continuously supported by competitively awarded federal grants since 1976; his research has been reported in over 300 peer-reviewed publications and in eleven patents. He has investigated the basic and clinical pharmacology of drugs, factors contributing to variable response to medicines, the medical management of arrhythmias, and the cardiac toxicity of drugs. While at Vanderbilt, Woosley was the co-director of the
NIH-sponsored Cardiac Arrhythmia Suppression Trial (CAST) that found arrhythmia suppression by drugs to be an invalid biomarker for the prediction of drug therapy that prevents sudden death. Woosley's research at Georgetown contributed substantially to the recognition that non-cardiovascular drugs, such as antihistamines (e.g., terfenadine (Seldane)), may have arrhythmogenic effects. Woosley's invention,
fexofenadine (Allegra), resulted from this research and is today marketed as a safer non-sedating antihistamine replacing Seldane. His research on drug safety led Woosley to champion the development of the Centers for Education and Research on Therapeutics (CERTs), until 2016, a network of federally funded centers designed to improve outcomes in medical therapeutics. In 2002, Woosley's research discovered the primary mechanism of methadone-induced sudden death. His subsequent research on methadone resulted in the addition of warnings to the official label. As President of AZCERT, he leads a team of scientists that maintains web-based lists of the drugs that have this potential toxicity; this website, with over 1,100 visits daily and over 66,000 registered users, is an internationally recognized resource cited in textbooks and used by researchers to evaluate the impact of drug safety programs. ==Leadership and service==