When medication no longer works

What mechanisms lead to the loss of efficacy of drugs? What factors favour resistance to therapy, and what innovative approaches can overcome them? This work offers a well-founded and systematic analysis of the complex relationships between drug efficacy and resistance. It sheds light on the biological, pharmacological and social background, examines the causes of treatment failure and presents practical solutions. The first part comprehensively explains the theoretical foundations of drug efficacy in order to create a thorough understanding of the underlying processes. Building on this, the second part analyses the diverse causes of the loss of efficacy, including pharmacodynamic and pharmacokinetic mechanisms. The third part is dedicated to specific strategies for overcoming resistance to therapy, including individualised therapeutic approaches and innovative technologies. The fourth part focuses on societal and scientific perspectives, such as the role of research, ethics and politics in the further development of therapies. Finally, the work offers practical guidance for professionals and those affected, in order to open up new avenues in therapeutic practice. An indispensable guide for scientists, physicians, pharmacists and anyone dealing with the challenges and opportunities of modern therapies - precise, evidence-based and forward-looking. 1. Auflage 2025