New Delhi: A study that has estimated which and how many antibiotics a country could be expected to ideally use has found that almost all countries are overusing 'watch' antibiotics, which contribute the most to antibiotic resistance when overused.
The 'watch' class is composed of stronger drugs that should be saved for conditions where simpler antibiotics won't work. The analysis is published in The Lancet Public Health journal.
Researchers, including those from the UK's University of London, have developed a framework, which they said can give countries a practical tool to assess whether their antibiotic use is broadly appropriate for their situation.
The method can also help address both overuse and the wrong use of certain antibiotics, they said.
The World Health Organization (WHO) classifies all antibiotics into three groups -- access, watch and reserve -- according to a drug's potential to cause resistance. 'Access' drugs such as amoxicillin are the first line treatments for the most common infections, while 'reserve' ones are the last resort, used against the most dangerous drug-resistant infections.
In 2024, the United Nations General Assembly agreed that the WHO Access, Watch, Reserve (AWaRe) system should form the basis for global antibiotic surveillance and that by 2030, at least 70 per cent of the global use should come from the Access group.
However, no method for deriving country-level targets was recommended, even as previous studies have reported estimates of antibiotic use in more than 200 countries and territories, the researchers said.
The team's framework groups countries into peer clusters based on shared characteristics, such as poverty levels, rates of infectious disease and antibiotic resistance.
Four clusters -- cluster one to cluster four -- were ordered from the lowest median gross national income per capita to the highest.
The researchers calculated that in 2019, around 43 billion courses of antibiotics were needed globally, averaging out to about one antibiotic course per person per year, to treat all bacterial infections.
They also estimated that about 77 per cent of the courses should have been 'access' group antibiotics -- the result suggested that the UN target of 70 per cent is reasonable.
Comparing the study's estimates with real-world data from 67 countries -- from the IQVIA MIDAS database -- the researchers found that nearly three-quarters of countries were using more antibiotics overall than needed.
"Of 67 CTAs (countries, territories and areas) with observed antibiotic use data available in our analysis, 72 per cent used higher total antibiotic volumes than expected and 99 per cent used more 'watch' antibiotics than expected," the authors wrote.
More than half of the countries and territories with available real-world data were not using enough 'reserve' antibiotics, meaning patients with life-threatening drug-resistant infections might not be receiving the treatments they need, the study found.
Further, 60 per cent of the countries were found to be still using antibiotics that WHO considers should no longer be prescribed.
India (in cluster two) was estimated to have an optimal total defined daily doses (DDD) per 1000 inhabitants per day (DID) ranging between 9.9 and 14.7, while the actual DID was 18.3. DID of 'watch' antibiotics formed the major part of the actual DID at 9.3, and 'access' DID was 4.5.
The researchers highlighted a global inequality -- low and middle income countries, which face heavier burdens of infectious disease and drug resistance, need proportionally more of the specialised watch and reserve antibiotics, compared to wealthier nations.
However, higher-income countries are currently using these types of antibiotics the most, they said.
The authors called for national policies to both reduce unnecessary prescribing and improve access for patients who genuinely need the medicines.
