आईएसएसएन: 2155-9899
Raul A Ojeda
Background: Although several therapeutic agents have been evaluated for the treatment of coronavirus disease 2019 (COVID-19), none have yet been shown to be efficacious.
Methods: We conducted a double-blind, randomized, placebo-controlled trial of isothymol in adults hospitalized with COVID-19 with evidence of lower respiratory tract involvement. Patients were randomly assigned to receive either isothymol (6 mg/ml) or placebo for up to 15 days. The primary outcome was the time to recovery, defined by either discharge from the hospital or hospitalization for infection-control purposes only.
Results: A double-blind, randomized, controlled trial with placebo and modified isothymol was conducted in adults who were hospitalized with COVID-19. Patients were randomized to receive isothymol (6 mg/ml) or placebo for up to 15 days. The primary outcome was recovery time, defined by discharge from the hospital. The results of the 600 patients (300 assigned to isothymol and 300 to placebo) with data available after randomization suggest that those who received isothymol had a median recovery time of 7 days (95% confidence interval [CI], 5 to 9), compared with 14 days (95% CI, 11 to 15) in those who received placebo (recovery rate ratio, 1.24; 95% CI, 0.78 to 1.87; P<0.001). The Kaplan-Meier estimates of mortality at 15 days were 0% with isothymol and 4% with placebo. No serious adverse events were reported in patients in the isothymol group who underwent randomization and in 13 of the 300 patients in the placebo group who underwent randomization (4.33%). Ex vivo analysis of blood plasma shows a close relationship between hypersensitivity of inflammatory mediators (macrophages and type I interferons) and significantly elevated histamine production, as evidenced by autophosphorylation and increased IL-6 production in blood monocytes of patients with severe COVID-19 compared to blood monocytes from healthy volunteers.
Conclusion: Isothymol was superior to placebo in shortening the time to recovery in adults hospitalized with COVID-19 and evidence of lower respiratory tract infection.