Question

 

Overview of the Pharmacodynamic Properties of (Dexamethasone & how it's related to COVID-19)

Answer 1

Dexamethasone is a corticosteroid, that is widely used in the treatment of inflammatory and autoimmune disorders including rheumatoid arthritis, thrombocytopenia, and bronchospasm.The blockage of the airway called croup which is common in children can be treated with a dose of dexamethasone . Dexamethasone is bind to specific nuclear steroid receptors to initiate the mechanism of action of anti-inflammation and immuno-suppression.

Mechanism of action - dexamethasone bind to the DNA of glucocorticoid properties to modify transcription proteins inhibiting leukocyte infiltration to the site of inflammation, interfering with the effect of inflammatory mediators, suppress humoral responses and reduce edema and/or scarring of tissues.

COVID-19 causes rapid accumulation of cytokines majorly IL-6 in the lungs. IL-6 is responsible for increasing inflammation in the lung cavity which causes the production and accumulation of fluids in the lungs. And dexamethasone being a steroid whose mechanism is of reducing inflammation and suppressing immune activation of immune agents, the drug could be inducing the anti-inflammatory effects and reducing the secretion of cytokines into the lungs. This improves the outcome of patients with high morbidity i.e patients severely ill and on ventilation by relieving the symptoms of the lung effects.

The sickest patients with COVID-19 suffer a hyperinflammatory state—a cytokine storm—that has features in common with a rare haematological condition called haemophagocytic lymphohistiocytosis. Immune suppression should help such patients. By contrast, immune suppression during the early phase of the viral infection might allow increased viral replication and aggravate the disease. The 3C-like proteinase on SARS-CoV-2 (nsp5) inhibits HDAC2 transport into the nucleus, and so impairs the way in which it mediates inflammation and cytokine responses, so activation of histone deacetylase by dexamethasone may directly oppose the action of SARS-CoV-2.