This book covers nutrients, active principles from phytotherapy/herbal products, and drug classes while identifying potential interactions. Didactic approaches to drug and non-drug interactions and cutting-edge reports are included in each chapter that promotes safer drug prescription and use. The physiopathological overview in this book provides background for chemistry, pharmacology, and mechanistic bases of drug and non-drug interaction as well as clinical cases and predictive screenings. This book is intended for undergraduate students studying medicine, nursing, nutrition, biomedicine, and pharmacy.