Antibiotic and antiviral prescribing patterns among hospitalised patients with COVID-19 pneumonia in Mongolia: a real-world descriptive retrospective study.

Background: During the COVID-19 pandemic, Mongolia, like many low- and middle-income countries, faced major healthcare delivery challenges due to limited system readiness, resource constraints, geopolitical vulnerabilities, and prolonged border closures. These factors caused shortages of laboratory reagents and globally recommended therapeutics, including remdesivir and tocilizumab, prompting clinicians to use alternative antivirals and empirical broad-spectrum antibiotics. Objective: To evaluate and compare real-world prescribing patterns of antibiotics and antivirals among hospitalised patients with COVID-19 pneumonia at Mongolia's two largest tertiary referral facilities: Mongolia-Japan Hospital (MJH) and the National Center for Communicable Diseases (NCCD). Methods: This retrospective cross-sectional study analysed anonymised medical charts and electronic health records of 1012 adults with PCR-confirmed COVID-19 pneumonia hospitalised between 18 April and 31 December 2021. Demographics, comorbidities, laboratory markers, and pharmacological treatments were systematically extracted and compared between the two institutions. Results: Antibiotics were prescribed to 87.6% (887/1012) of patients. Cephalosporins were the most frequently prescribed class (89.3%, 904/1012), followed by macrolides (36.5%, 369/1012) and fluoroquinolones (33.5%, 339/1012). Multi-drug empiricism was common, with beta-lactam, macrolide, and quinolone combinations accounting for 70.8% (68/96) of triple-antibiotic regimens. Antivirals were administered to over 90% of patients, predominantly umifenovir (52.2%) and favipiravir, supported by domestic stockpiles and Eurasian trade networks. Remdesivir was rarely used, while tocilizumab was administered to only 2 patients (0.2%). Hypertension and diabetes were significantly more frequent in the MJH cohort, reflecting differences in catchment populations and screening practices. Conclusion: The high rate of empirical broad-spectrum antibiotic use and reliance on alternative antivirals reflect pragmatic clinical adaptations to diagnostic reagent shortages and therapeutic supply inequities. These findings highlight the need for national antimicrobial stewardship programmes, strengthened microbiological diagnostic capacity, and digitised clinical registries to improve healthcare system resilience in resource-constrained settings.