Idiosyncratic adverse drug reactions (IADRs) typically occur only in a small fraction of patients who are treated with certain drugs at therapeutic doses. IADRs are usually unrelated to the pharmacological target of the drug. They present a serious human health problem and are usually not predicted by current preclinical safety evaluation during drug development. During the period 1975-2000, 10% of newly approved drugs were withdrawn from the U.S. market or received black box warnings due to these adverse reactions Uetrecht, 2007) .