Researching ‘the right dose’ critical to saving lives

23 Feb 2021

Antibiotic dosing software research at The University of Queensland will look at ways of giving critically ill patients the best chance at survival and a successful recovery.

UQ Centre for Clinical Research NHMRC Practitioner Fellow Professor Jason Roberts received a $499,950 Queensland Advancing Clinical Research Fellowships grant to undertake optimising antibiotic dosing for critically ill patients.

Professor Roberts said his team led a number of studies which found a very strong clinical relationship between achieving a therapeutic antibiotic concentration and improved likelihood of clinical cure for patients, or improved survival.

“The need for finding better antimicrobial dosing for patients in intensive care is undoubted, but the final challenge was how to get to that better dose,” he said.

“And that is what this grant relates to, how we ensure patients get these better doses and what methods we apply,” he said.

"There are two principle methods we will be exploring over the next four years and the first relates to dosing software, where we have mathematical models that are embedded in computer software.

“Those models contain descriptors of the effects of different patient characteristics on antibiotic requirements.”

Professor Roberts said patients with good kidney function tended to require a higher dose than a patient with worse kidney function, given that most antibiotics are removed through the kidneys.

“So the better the kidneys work the more we need to adjust our dosing upward to ensure they are still getting an effective concentration of antibiotics in their body,” he said.

“The software allows us to input patient-specific information that can be used to calculate a dose which is personalised to the individual needs of the patient.”

Professor Roberts said that while that process made a lot of sense, it hadn’t been previously explored in critical ill patients for several reasons.

“Those reasons are more related to infrastructure and training, but we have overcome those challenges at the Royal Brisbane Women’s Hospital, so our job during this fellowship will be to quantify what the benefits of dosing software are compared to just standard dosing,” he said.

“Antibiotics are so very important in patients with severe infections. If you miss starting an appropriate antimicrobial by as little as half an hour, the likelihood of death increases by six per cent, highlighting how important appropriate and effective antibiotics are.”

Sepsis, a serious infection, is an ever-present enemy for critically ill patients.

“Sepsis is the most common cause of death and healthcare complications in patients that are admitted to the intensive care unit, and the best intervention is optimal antibiotic use,” Professor Roberts said.

“There are two ways to do this, starting with administering the antibiotics in a timely manner,” he said.

“The second component, which is the focus of this research program, is to administer them at a dose which is going to enable rapid killing of the bacteria, so the patient can return to normal function because it tends to be the infection which really derails their clinical progress.”

Professor Roberts is also a Consultant Clinical Pharmacist at the Royal Brisbane and Women’s Hospital

Media: Professor Jason Roberts, 3365 5118;  Faculty of Medicine Communications, 3365 5118, 0436 368 746.