National trends in antimicrobial consumption in Nepal, 2016–2023: an ecological analysis

Objective To characterize class-specific national antimicrobial consumption patterns in Nepal from 2016 to 2023 and explore monotonic and linear temporal patterns, differences between the 2016–2019 and 2020–2023 periods, and the influence of selected high-consumption years.Methods We conducted a retrospective ecological analysis of five antimicrobial classes using annual national consumption expressed as Defined Daily Doses per 1,000 inhabitants per day (DID). Descriptive statistics summarized consumption; Mann–Kendall tests and linear regression explored temporal patterns; an exploratory period comparison assessed 2016–2019 versus 2020–2023; and sensitivity analyses assessed the influence of selected years.Results Antibacterial agents had the highest mean consumption at 48.6 defined daily doses per 1,000 inhabitants per day (DID). Considerable year-to-year variability was observed across antimicrobial classes, with limited evidence of sustained temporal trends over the short observation period. Anti-tuberculosis drug consumption showed evidence of an upward monotonic pattern in the Mann-Kendall analysis. However, this finding was not supported by a statistically clear linear trend and was sensitive to exclusion of the 2023 value. Exploratory comparisons of the 2016–2019 and 2020–2023 period showed imprecisely estimated differences in antibacterial and antifungal consumption.Conclusion National antimicrobial consumption in Nepal showed substantial class-specific and year-to-year variation during 2016–2023. The short time series limits inference regarding sustained long-term trends, and the apparent upward pattern in anti-tuberculosis drug consumption should be interpreted cautiously.