In Memoriam: George Louis Drusano

George L. Drusano, MD, one of the most influential figures in modern infectious diseases and pharmacology, passed away at the age of 76 years on June 10, 2025, in Orlando, Florida, USA. In the words of Dr. Thomas P. Lodise, PharmD, PhD, a Professor and Endowed Research Chair at the Albany College of Pharmacy and Health Sciences, “George Drusano was a giant in the field of antimicrobial pharmacokinetics and pharmacodynamics (PK/PD), laying the foundation for modern anti-infective therapy.” Born on August 22, 1949, in Baltimore, Maryland, Dr. Drusano graduated from Loyola High School in 1967 and earned a Bachelor of Science degree from Boston College in 1971. He received his Doctor of Medicine degree from the University of Maryland School of Medicine in 1975, where he also completed his fellowship in infectious diseases and began his distinguished academic and clinical career caring for patients with HIV. In 1992, Dr. Drusano joined Albany Medical Center Hospital as Director of Clinical Pharmacology and Associate Director of the Clinical Research Institute. He later became the founding Director of the Institute for Therapeutic Innovation at the University of Florida, where he led a pioneering research program focused on translational antimicrobial pharmacology. Dr. Drusano received numerous awards and honors recognizing his exceptional contributions to science and medicine. These included the Rhone-Poulenc Award at the International Congress of Chemotherapy (1991) for his innovative research on fluoroquinolones; the American Society of Health-System Pharmacists Research and Education Foundation Drug Therapy Research Award (1998); and the Maxwell Finland Award for Scientific Achievement (2012) for his groundbreaking work in anti-infective pharmacology and antimicrobial resistance. Dr. Drusano delivered countless presentations at leading international conferences, advancing the treatment of difficult-to-treat infections such as tuberculosis and HIV. His research also contributed to national defense efforts through studies aimed at preventing and countering bioterrorism and the use of biological weapons. With an extensive body of publications in high-impact scientific journals, he continuously shared insights that shaped modern antimicrobial pharmacology. His pioneering “bench-to-bedside” research revolutionized antibiotic dosing practices worldwide and profoundly influenced generations of clinicians and scientists. He was a fellow of the Infectious Diseases Society of America and the American Academy of Microbiology, served as President of the International Society for Anti-Infective Pharmacology, contributed to the program committee of the Interscience Conference on Antimicrobial Agents and Chemotherapy, and was a long-serving pharmacology editor for Antimicrobial Agents and Chemotherapy. Dr. Drusano’s work fundamentally reshaped how antimicrobial therapy is conceived, tested, and optimized. Over a career spanning more than four decades, he pioneered the integration of PK/PD into antimicrobial regimen design, transforming what had been an empirical art into a quantitative, predictive science. His central insight was that the relationship among drug, pathogen, and host could be mathematically defined, simulated, and optimized to achieve maximal bacterial killing while minimizing the emergence of resistance. Through this framework, he advanced anti-infective research from descriptive observation to mechanistic understanding, laying the foundation for model-informed precision dosing that underpins modern clinical pharmacology and regulatory science. Drusano’s scientific contributions were both technically groundbreaking and conceptually transformative. He helped advance and refine translational systems, most notably the hollow-fiber infection model and neutropenic murine thigh and lung models that enabled precise characterization of dynamic drug–pathogen interactions under controlled, physiologic conditions.1 Through his innovative application and quantitative interpretation of these platforms, he established their central role in linking preclinical findings to human dosing regimens and defining exposure–response relationships across antimicrobial classes such as β-lactams, fluoroquinolones, aminoglycosides, oxazolidinones, and antitubercular agents. His introduction of stochastic forecasting, or Monte Carlo simulation, marked another watershed in anti-infective pharmacology.2 This approach enabled population-based projections of drug exposure and bacterial kill probabilities, allowing investigators to identify optimal dosing regimens and justify susceptibility breakpoints with a level of rigor and predictive accuracy previously unseen in infectious diseases research. Equally transformative was Dr. Drusano’s pioneering work in modeling antimicrobial combination therapy. Recognizing that multidrug regimens could achieve greater bacterial kill and resistance suppression than any single agent alone, he developed mathematical and experimental models to identify optimal combinations, dosing ratios, and scheduling strategies.3 His work elucidated how drug–drug interactions could shift therapeutic outcomes, from synergy to antagonism, and how such interactions could be quantitatively predicted and experimentally validated.4 Through these efforts, he provided the scientific framework for rational design of combination therapies for complex infections such as Mycobacterium tuberculosis, Pseudomonas aeruginosa, and Acinetobacter baumannii, and for viral diseases including HIV and influenza.5 By uniting quantitative modeling with biological realism, Dr. Drusano turned combination therapy development from a trial-and-error process into an evidence-based scientific discipline, guiding countless preclinical and clinical programs across academia, industry, and government. A hallmark of Dr. Drusano’s research was his focus on resistance suppression.6 He was among the first to demonstrate that antibiotic dosing could be optimized not only for efficacy but also to prevent the emergence of resistant subpopulations. His models revealed how subtherapeutic exposures foster resistance, and how combination regimens could be engineered to both eradicate pathogens and block mutation-driven survival. These concepts now underpin modern strategies for combating multidrug-resistant organisms and have directly informed global antimicrobial development programs. Through his intellect, precision, and relentless curiosity, George Drusano advanced antimicrobial pharmacology from empiricism to predictive science. His work provided the methodological and conceptual architecture that now guides dose selection, resistance management, and model-informed clinical trial design across the infectious diseases landscape. His legacy endures not only in the therapies that save lives each day but in the quantitative framework that defines PK/PD modeling and combination therapy optimization, a scientific foundation he helped build and elevate into one of the most powerful tools in modern medicine. It is now up to us, his colleagues, mentees, and friends, to carry forward his legacy. We honor his memory by advancing the science he pioneered and upholding the PK/PD principles that guided his work, ensuring his impact on patient care and antimicrobial research endures for generations to come.