Dexamethasone vs COVID-19: An experimental study in line with the preliminary findings of a large trial

The preliminary report of the RECOVERY large randomised controlled trial indicated a promising survival effect for dexamethasone therapy of coronavirus disease 2019 (COVID-19). This study aimed to investigate the anti-hypoxic activities of dexamethasone to understand a possible mechanism of its action in hypoxia-induced lethality through experimental models of hypoxia.

In this investigation, 84 Male BALB/c mice were randomly divided into groups of seven (12 groups). Treatment groups received 10 days of dexamethasone intraperitoneal injection at both human dose (~0.1 mg/kg) and the animal does (~1 mg/kg). Control negative and positive groups were treated with 10 ml/kg of normal saline and 30 mg/kg of propranolol, respectively. Three experimental models of hypoxia, asphyctic, circulatory, and hemic were applied in this study.

The findings showed that dexamethasone significantly prolonged the latency for death in the asphyctic model concerning the control group in both humans (P < .0001) and animal dose (P < .0001). The results were also highly significant for both doses in the hemic model (P < .001). In the circulatory model, although a small increase was observed in death prolongation, results were not statistically significant for both doses in this model (P > .05).

This experimental in vivo investigation demonstrated an excellent protective effect for 10 days of dexamethasone treatment against hypoxia, especially in asphyctic and hemic models. In addition to promising dexamethasone outcomes, using propranolol as the positive control illustrated a very substantial anti-hypoxic effect even much better than dexamethasone in all models. It seems that propranolol would be a safe, potential, and prudent choice to invest in treating COVID-19 patients.