Tocilizumab is an IgG1 class recombinant humanized monoclonal antibody that directly inhibits IL-6 receptor. Several randomized clinical trials (RCTs) have evaluated tocilizumab’s safety and efficacy in patients with COVID-19. These studies demonstrated conflicting results regarding tocilizumab’s efficacy and safety. Our study aim is to determine the association between treatment with tocilizumab and emergence of multidrug-resistant bacteria and its effect on mortality in critically ill patients with Coronavirus disease 2019 (COVID-19).
A multicenter, retrospective, cohort study conducted at two governmental tertiary hospitals in Saudi Arabia. All critically ill patients who were admitted to intensive care units (ICUs) with a positive COVID-19 PCR test between March 1st, 2020 and January 31st, 2021 were included. Patients who received tocilizumab were compared to patients who did not receive it.
A total of 738 patients met our inclusion criteria and were included in the analysis. Of these 262 (35.5%) received tocilizumab and 476 (64.5%) were included in the control group. Patients who received tocilizumab did not have higher odds for the microbial isolation (OR 1.34; 95% CI, 0.91-1.94 p = 0.13), development of resistant organisms (OR 1.00; 95% CI, 0.51-1.98 p = 0.99), or detection of Carbapenem-Resistant Enterobacteria (CRE) (OR 0.67; 95% CI, 0.29-1.54 p = 0.34). In a multivariable logistic regression adjusting for possible cofounders, there was no difference in 30-day ICU mortality (OR 0.96; 95% CI, 0.65-1.43 p = 0.85) or in-hospital mortality (OR 1.18; 95% CI, 0.79-1.76 p = 0.42). However, there was a significant difference in the incidence of respiratory failure requiring MV between the two groups (OR 2.27; 95% CI, 1.05-4.89 p = 0.03).
Tocilizumab use in critically ill COVID-19 patients was not associated with microbial isolation, emergence of resistant organisms, detection of CRE organisms, or mortality benefits. However, tocilizumab use was associated with an increased risk of respiratory failure requiring mechanical ventilation.