Hiyang

In everyday Filipino life, the word hiyang carries profound meaning. A person might say, 'hiyang sa akin ang gamot na ito' (i.e., this medicine suits me) or lament that a treatment is 'hindi hiyang.' For generations, Filipinos have used this term to capture the mystery of why some remedies work for certain people but not for others. What once seemed like cultural intuition is now at the center of a rapidly advancing science: pharmacogenetics.Pharmacogenetics is the study of how our genes influence drug response. It explains why two patients given the same dose of the same medicine may experience very different results: healing in one, side effects in another, or no effect at all. What Filipino families have long described through hiyang, science now investigates through enzymes, genetic variants, and molecular pathways. This book builds a bridge between these worlds, showing that cultural wisdom and modern research are not enemies but partners in understanding human health.Across its chapters, the book introduces the fundamentals of pharmacogenetics in clear, accessible language. Readers learn about genetic polymorphisms in enzymes such as CYP450 and their impact on drug metabolism. They discover how pharmacogenetic testing guides treatment choices in cardiovascular disease, infectious diseases, and oncology. Alongside the science, the text interweaves stories and expressions of hiyang, illustrating how Filipinos have long recognized the principle that 'not all medicines fit all people.'Beyond the technical, the book raises questions at the intersection of ethics, culture, and medicine. What are the implications of pharmacogenetic testing in resource-limited settings? How can indigenous concepts like hiyang enrich global health conversations and promote cultural humility among practitioners? How do we ensure that advances in precision medicine remain accessible and equitable, rather than widening gaps in care?This is not just a scientific primer but also a cultural exploration. It speaks to physicians, pharmacists, students, and researchers who wish to understand pharmacogenetics in a broader human context. It also invites general readers to reflect on how everyday language encodes valuable insights into health. By situating hiyang within the global movement toward personalized medicine, the book offers a uniquely Filipino contribution to a universal challenge: making healthcare more precise, more personal, and more just.Ultimately, this book argues that healing has always been about finding the right fit, between person and medicine, between genes and treatment, between culture and science. Hiyang is more than a word; it is a bridge. And by crossing it, we discover new ways of thinking about medicine, identity, and the shared search for well-being in a diverse and interconnected world.