New thesis paving the way for precise antibiotic dosing

Antimicrobial resistance is defined by the World Health Organization as one of the biggest threats to global public health. In healthcare – where access to effective drugs against infections is essential – the needs for new tools are urgent. Despite the intensive search for new antibiotic classes, 40 years have passed since the latest addition to the arsenal. Alternative paths are now required, and in a new thesis, Maria Swartling at Uppsala University presents important clues to better use of existing antibiotics.

“Optimal dosage is a key component of every antibiotic-based treatment. Not least while providing intensive care, where conditions can quickly become life threatening. With individual dosage, both efficiency and safety increase, but this requires well-founded decisions. Today, digital software provides support to interpret the concentration of drugs in a body, so-called Model-Informed Precision Dosing, MIPD, and in my thesis we analyze the scope to implement MIPD in Swedish healthcare,” says Maria Swartling, PhD student at the Department of Pharmacy.

One obvious challenge is that patients often react individually to different antibiotics. Simply increasing the dose seldom offer the right way forward, and in her studies, Maria Swartling has instead evaluated extended infusion times of three antibiotics that are frequently used in intensive care. Her results show that 15 minutes of administration into the blood normally provide sufficient concentrations against simple infections, and above all: three hours or continuous infusion can generate sufficient levels to eliminate even more difficult-to-treat bacteria.

“This indicates that extended dosing enables more people to reach the target concentration. On the other hand, we see that many patients still have insufficient levels of antibiotics in their blood. With MIPD, we have the tool to identify already at an early stage which patients are at risk of under-treatment and adjusting the dose. Of course, taking MIPD into healthcare requires some initial investments, and in a pilot project at the Uppsala University Hospital, we are currently testing a new strategy for effective clinical implementation.”

The working model that is being tested at the hospital's Blood and Tumor Diseases Division includes a team-based process running from sampling to new dosing, with a pharmacist or physician assuming the role of MIPD consultant with the task to provide a dosage recommendation to the prescribing physician. The strategy to introduce the model includes an educational package where nurses participate in short briefings with focus on the importance of fixed routines for dose infusion, sampling and medical records. In addition, clinical pharmacists and physicians receive an introduction to the new working method.

“We have chosen to focus on introducing MIPD for vancomycin with a working method that involves the entire healthcare team from the start. Our pilot project will continue for another year before we begin the evaluation in 2026. If this approach proves successful, our hope is to make the model applicable to several other drugs and treatment areas,” states Maria Swartling.

text: Magnus Alsne, photo: Mikael Wallerstedt a o