A new international study led by researchers from the Kirby Institute at UNSW Sydney and UCLA has found that long-acting antibiotics are just as effective as standard daily antibiotics for serious infections – and could offer major benefits for people who face barriers to healthcare, including people who use drugs. The study was recently published in JAMA Network Open.
“These findings could be a game-changer,” said Dr David Goodman-Meza, an infectious diseases and addiction medicine physician and researcher at the Kirby Institute. “Such an approach could help reduce hospital stays and may offer more autonomy for patients navigating substance use and housing instability.”
Serious bacterial infections like bloodstream infections, bone and joint infections or heart valve infections usually require weeks of intravenous (IV) antibiotics. But for some patients, including those experiencing homelessness or substance-use disorders, it’s not always possible to stay in hospital for extended periods or manage daily IV care at home.
Researchers from the Kirby Institute wanted to understand whether long-acting antibiotics – that can stay active in the body for weeks after a single dose, meaning patients might only need one or two doses – could provide an alternative treatment option. These antibiotics have been approved in Australia and internationally for skin and soft tissues infections but have not been approved for more serious infections that typically require longer durations of antibiotics treatments.
“We wanted to know whether these long-acting treatments could offer a safe and effective alternative to the standard daily antibiotic regimens for serious infections,” said Dr Goodman-Meza, lead author of the research paper.
To find out, the team studied data from more than 42,000 people across the US who were treated for serious bacterial infections between 2015 and 2022. They compared people who received long-acting antibiotics with those who received standard antibiotic treatment and looked at whether patients were readmitted to hospital, went to the emergency department or died within 90 days. This type of study is called ‘target trial emulation’, and it uses real-world health data to simulate the results of a clinical trial. This approach is becoming increasingly important when trials are not feasible or ethical, especially in under-researched groups like people who use drugs.
“We specifically looked at people with a recent history of drug use, as well as people without drug use,” explained Dr David Goodman-Meza. “This is important, because people who use drugs stand to benefit from long-acting antibiotic options, as they are at higher risk of these infections, while the long-acting option removes the need for daily IV access, intensive monitoring or lengthy hospital stays. Furthermore, people who use drugs routinely get excluded from large clinical trials often due to concerns about adherence, follow-up or comorbidities, so including this key population in this study was important to us.”
The results showed no difference in outcomes, meaning the newer, more convenient treatment option was just as effective. This was true for both the general population and for people with a recent history of drug use.
This is the largest study to date evaluating the effects of long-acting antibiotics. While long-acting antibiotics are currently approved for skin infections, this study supports expanding their use for more complex infections, particularly when traditional care is not practical.