Greenhouse gas emissions due to unnecessary antibiotic prescriptions

Scope 3 includes all healthcare-related indirect emissions across fifteen categories, one of which is indirect emissions associated with the production and distribution of pharmaceuticals.2 Overall, pharmaceuticals account for approximately 18% of scope 3 emissions.2 One potential strategy to mitigate harmful emissions is to measure emissions encompassed in Scope 3 in the form of waste associated with medications lacking a clear indication. 30%–50% of antibiotic use across US healthcare is unnecessary.3 Antibiotic Stewardship encompasses efforts to measure and improve antibiotic prescribing with the goal of minimizing unintended consequences of unnecessary antibiotic prescribing. Estimates of waste emissions due to unnecessary outpatient antibiotic prescriptions in the US, 2014–2015 Estimated mean no. of antibiotic prescriptions Estimated no. of unnecessary antibiotic prescriptions Paper weighta Paper landfilled waste emissions (MT CO2 e/ton)b Plastic weightc Plastic landfilled waste emissions (MT CO2 e/ton)d Total landfilled waste emissions (MT CO2 e/ton) Greenhouse Gas Equivalent in miles driven by an average gasoline-powered vehicle < 20 years of age 48,500,000 13,580,000 434,560 kg 383.216 203,700 kg 4.491 387.707 993,906 ≥ 20 years of age 187,600,000 52,528,000 1,680,896 kg 1482.296 787,920 kg 17.371 1499.667 3,844,470 Total 236,100,000 66,108,000 2,115,456 kg 1865.512 991,620 kg 21.862 1887.374 4,838,375 a Weight of paper leaflet = 22g; weight of paper bag = 10 g. b Emissions factor of 0.80. c Weight of plastic bottle = 15g. d Emissions factor of 0.02. Discussion To our knowledge, this is the first evaluation of the impact of unnecessary antibiotics in humans on greenhouse gas emissions, and we estimated annual unnecessary outpatient antibiotic prescriptions contribute the same emissions as driving an average gas-powered car around the Earth 194.3 times.