US Antibiotic Importation and Supply Chain Vulnerabilities.

Importance: The US has faced persistent antibiotic shortages over the past decade, compromising patient care, public health, and national security. Understanding the global sources of US antibiotic imports is critical to inform policies to improve supply chain resilience. Objective: To identify the global sources of US antibiotic imports, focusing on finished dosage forms (FDFs) and active pharmaceutical ingredients (APIs) between 1992 and 2024. Design and Setting: This cross-sectional study of US antibiotic importation records used data from USA Trade Online from January 1992 to July 2024. Data included import volumes, costs, and the originating country. Main Outcomes and Measures: Trends in annual import volumes for antibiotic FDFs and APIs (metric tons), spending and price per kilogram (inflation-adjusted dollars), and market concentration measured by the Herfindahl-Hirschman Index (HHI). An HHI less than 1500 indicates an unconcentrated (ie, competitive) market, 1500 to 2500 indicates a moderate concentration, and greater than 2500 indicates high concentration. Results: The final sample included 50 FDF-originating countries and 52 API-originating countries. Compared with the annual volume of US antibiotic FDF imports in 1992, the annual volume in 2024 increased 2595.0%, while the annual volume of API imports remained relatively stable. Mean inflation-adjusted importation prices for FDFs decreased from $1836.03 per kg in 1992 to $177.44 per kg in 2024. For APIs, mean prices decreased from $351.74 per kg in 2003 to $65.69 per kilogram in 2024. From 2020 to 2024, India was the leading originating country for FDFs (31.9% of the total imported volume and 18.2% of the total imported cost), followed by Italy (13.4% of the total volume and 22.4% of the total cost). China was the leading originating country for APIs (62.6% of the total imported volume and 28.7% of the total cost), followed by Bulgaria (16.1% of the total volume and 3.8% of the total cost). Italy was the originating country for 2.6% of API imported volume but accounted for 27.9% of the importation costs. HHI revealed that FDF importation has become unconcentrated since 2020 (HHI, 1500-2500), while API importation markets are highly concentrated (2024 HHI, >5000). Conclusions and Relevance: This study found that US antibiotic importation relies on diversified global sources for FDFs but primarily on China for APIs. Policies to strengthen domestic production and diversify sourcing are critical to mitigate supply chain vulnerabilities. Improved traceability and targeted strategies for specific antibiotics are recommended to safeguard public health and national security.