In the arena of treating invasive group A streptococcal (GAS) infection in adults, linezolid is emerging as a promising alternative for adjunctive antitoxin therapy. This is based on the findings from a large scale, multicenter, retrospective non-inferiority study of adult inpatients, published in The Lancet Infectious Diseases.
Conducted from 2016 to 2021, the study offers compelling insights into the efficacy and potential benefits of linezolid, especially in patients already receiving β-lactam therapy. The study, which also employed a statistical analysis via a propensity score matching approach, examined cases from a whopping 1103 hospitals across the United States. A pool of 1095 patients was studied, all of whom had completed at least three days of β-lactam therapy. A significant chunk (76%) received clindamycin, while the remaining 24% received linezolid as adjunctive therapy.
Researchers observed the primary outcome of in-hospital mortality as well as secondary outcomes such as the length of hospital stay among survivors and the occurrence of Clostridioides difficile infection. Various factors such as patient demographics, inflammation measures, and antibiotic resistance were also taken into account. Interestingly, linezolid recipients tended to display higher rates of discharge to hospice and mortality compared to clindamycin recipients.
However, after methodical adjustment for residual confounders, there was no concrete association between the use of linezolid and in-hospital mortality, making it just as effective as clindamycin. Furthermore, there were no significant disparities witnessed between clindamycin and linezolid recipients in terms of median length of hospital stay or the occurrence of C. difficile.
Researchers widely advocate for consideration of linezolid as the acceptable first-line adjunctive therapy, especially given the unpredictable clindamycin resistance among GAS isolates worldwide. Despite the breakthrough findings, certain limitations of the study were also acknowledged, including the modest number of deaths, the application of emulation trial methodology, and the potential for residual confounding.