Large-scale drug safety surveillance and pharmacovigilance are key components of effective drug regulation systems, clinical practice, and public health programs. Although the efficacy and safety of a drug must be demonstrated in a series of clinical trials prior to approval, many adverse drug events (ADEs) are detected only after a drug has been marketed when it is used by a larger and more diverse population than during clinical trials. Adverse drug events discovered after a drug is in broad use can be a significant cause of morbidity and mortality. Thus, effective and accurate post-market drug surveillance is in urgent demand for the protection of public health and the reduction of healthcare expenditures due to ADE-related hospital complications.