Our four studies highlight the importance of potential drug-drug interactions as a contributing factor in drug safety. Thus, this book contains these studies starting with the evaluation of drug interaction screening programs, continuing with the prevalence of drug-drug interactions during hospitalization and the pharmacist intervention study and ending with a case-control study about risk factors for gastrointestinal bleeding. We conclude, that improvements regarding the awareness of potential drug-drug interactions and a strict management should be implemented. Prescribing drugs with a low...