Efficacy of Glycyrrhizic Acid Preparations in Severe or Critical COVID-19 Patients: A Retrospective Observational Study

Background/Aims Glycyrrhizic acid (GA) has demonstrated promising efficacy in patients with mild COVID-19, however, its applicability in severe and critical patients needs more substantial evidence. This study aimed to evaluate the effectiveness of GA in this patient population and to explore whether an extended treatment course could provide additional clinical benefits. Methods This retrospective study enrolled 73 patients with severe or critical COVID-19. Based on their receipt of GA therapy, patients were divided into an observation group (received GA therapy) and a control group (did not receive GA therapy). The primary outcome was in-hospital all-cause mortality. The mortality between the two groups was compared using survival analysis, and a multivariate logistic regression model was further employed to identify independent predictors of mortality. Results The all-cause mortality during hospitalization was significantly lower in the observation group than in the control group (P = 0.005). Furthermore, survival curves demonstrated a significantly lower mortality rate in the observation group (P = 0.039). Patients in the observation group also had significantly shorter durations of corticosteroid use and median hospital stays among survivors. By hospital day 14 or at discharge, the observation group exhibited more pronounced improvements in inflammatory markers and a higher rate of improvement on lung CT imaging. In a subgroup analysis of patients who received GA therapy, the long-course group showed lower mortality than the short-course group (10.71% vs. 27.78%), although this difference did not reach statistical significance (P = 0.059). However, the difference in survival curves between these two subgroups reached borderline statistical significance (P = 0.051). Multivariate regression analysis identified non-receipt of GA therapy as an independent risk factor for mortality. Conclusion GA therapy may confer benefits in delaying disease progression and reducing mortality among patients with severe or critical COVID-19. Furthermore, increasing the dosage or extending the treatment course represent viable strategies to potentially enhance its clinical efficacy.