Beta-Lactam Antibiotics: Can Blood Tests Improve Dosing?

Why did COVID-19 increase concerns about antibiotic resistance?

The CDC reports that resistant infections beginning in hospitals, and deaths associated with those infections, each increased by at least 15% from 2019 to 2020 across seven pathogens. Staffing shortages, equipment constraints and longer hospital stays complicated prevention. These findings describe the pandemic's early impact; they are not newly measured October 2026 infection rates. [CDC pandemic review](https://www.cdc.gov/antimicrobial-resistance/data-research/threats/covid-19.html).

A subsequent CDC update covering 2021–2022 found that six categories of resistant bacterial infections beginning in hospitals rose by a combined 20% during the pandemic compared with the preceding period. The burden peaked in 2021 and remained elevated overall in 2022. The treatment implication is that preserving antibiotic effectiveness requires attention to how existing medicines are used alongside infection prevention. Population surveillance alone cannot establish which dosing strategy improves an individual patient's outcome. [CDC resistance update](https://www.cdc.gov/antimicrobial-resistance/data-research/threats/update-2022.html).

How can blood tests personalize beta-lactam antibiotic doses?

Beta-lactam antibiotics are widely used for serious bacterial infections. In acutely ill patients, the same prescribed dose can produce substantially different blood concentrations. Kidney function influences drug clearance, but standard dosing estimates do not capture every patient's response. Measuring concentrations provides additional information about the exposure actually achieved.

Consensus guidance published in July 2026, endorsed by the Infectious Diseases Society of America and other professional organizations, addresses the evidence and practical requirements for individualized dosing. It combines systematic evidence assessment with expert consensus where research is insufficient. The clinical objective is to improve effectiveness and safety while recognizing uncertainty about patient outcomes. [Beta-lactam dosing guidance](https://www.idsociety.org/practice-guideline/beta-lactam-antibiotic-dose-individualization-in-acutely-ill-patients/).

Does antibiotic drug monitoring improve sepsis outcomes?

The TARGET randomized trial, published in Intensive Care Medicine in 2022, enrolled 254 adults with sepsis or septic shock. Both groups received continuous infusions of piperacillin–tazobactam; one group's doses were guided by daily piperacillin measurements. Among 249 evaluable patients, monitoring increased attainment of the study's concentration target but did not significantly improve the primary outcome, a measure of organ dysfunction. [TARGET trial](https://pubmed.ncbi.nlm.nih.gov/35106617/).

Mortality and cure outcomes also showed no statistically significant differences. This distinction matters: reaching a laboratory target demonstrates a dosing effect, but does not by itself prove that patients recover faster or survive more often. The findings support further investigation into which patients benefit most. They do not establish that concentration monitoring reverses resistance or that every patient receiving this antibiotic needs testing.