(Vienna, 16-05-2025) An international panel of experts, including Markus Zeitlinger from the Medical University of Vienna, has presented a systematic review of the effect and dosage of antibiotics in patients with obesity. The results were published in the top journal "The Lancet Infectious Diseases" and will serve as a basis for future dosage recommendations in clinical practice.
Obesity can lead to changes in the body that affect the absorption, distribution and excretion of drugs. For many antibiotics, it is still unclear whether and to what extent these changes require a dose adjustment. The working group analysed over 120 studies on pharmacokinetics – i.e. the distribution of active substances in the body – and evaluated the quality of the available data.
The evaluation shows that for certain groups of antibiotics, such as aminoglycosides and glycopeptides, increased body weight clearly influences the concentration of the active substance in the body. In these cases, a dosage based on "adjusted bodyweight" is recommended – i.e. a mathematically adjusted weight value that avoids extreme dosage errors. For other commonly used antibiotics such as β-lactams (e.g. penicillins or cephalosporins), the data also show changes, but the standard dosages used to date are sufficient in most cases. Where there is uncertainty, the use of therapeutic drug level monitoring is recommended.
Markus Zeitlinger, Head of the Department of Clinical Pharmacology at MedUni Vienna, emphasises: "Antibiotic therapy in people with obesity has hardly been systematically investigated to date. This work will help to enable better, scientifically based treatment for this growing patient group."
Publikation: The Lancet Infectious Diseases
The pharmacokinetics of antibiotics in patients with obesity: a systematic review and consensus guidelines for dose adjustments
Anne-Grete Märtson, Katie E Barber, Ryan L Crass, Maya Hites, Charlotte Kloft, Joseph L Kuti, Elisabet I Nielsen, Manjunath P Pai, Markus Zeitlinger, Jason A Roberts, Thomas Tängdén, on behalf of the Pharmacokinetics and Pharmacodynamics of Anti-Infectives Study Group of the European Society of Clinical Microbiology and Infectious Diseases, the International Society of Anti-Infective Pharmacology, and the Society of Infectious Diseases Pharmacists
https://www.thelancet.com/journals/laninf/article/PIIS1473-3099(25)00155-0/fulltext