Why small molecules still matter in the global fight against infection

The world is facing a critical shortage of effective antibiotics, driven by rising antimicrobial resistance (AMR), limited access to treatments, and a failing market for new drug development. Despite the growing appeal of alternative approaches like phage therapy and biologics, small-molecule antibiotics remain the most practical and scalable solution for controlling bacterial infections—especially in low- and middle-income countries (LMICs), where the burden of disease is highest.

This review argues that the need for new, affordable, and accessible small-molecule antibiotics is urgent and multifaceted. While resistance is a major concern, most global deaths from bacterial infections still result from treatable, drug-sensitive strains. The challenge is not just drug resistance, but drug inaccessibility, suboptimal treatment, and bacterial tolerance—particularly in vulnerable populations with chronic infections or compromised immune systems.

Scientific hurdles include the complex physiology of bacteria in real infection environments, drug penetration barriers in Gram-negative pathogens, and the failure of high-throughput screening to identify truly novel compounds. Economic roadblocks are equally daunting: the cost of developing a new antibiotic often exceeds $1 billion, while returns are modest due to stewardship efforts and short treatment courses. As a result, many companies have exited the antibiotic market entirely.

Solutions require coordinated global efforts. Strategies include expanding nonprofit and government-funded R&D, implementing subscription payment models for antibiotic access, developing better diagnostic tools, and embracing more flexible definitions of success, such as narrow-spectrum drugs and combination therapies. If properly supported, small-molecule antibiotics can continue to serve as the cornerstone of infectious disease treatment in an increasingly complex global health landscape.