Pharmacogenomic considerations for repurposing of dexamethasone as a potential drug against SARS-CoV-2 infection

Lay abstract The surge of COVID-19 cases has increased the need for the development of a cure. This has pushed the barriers of the regulatory controls for randomized controlled trials. There has been the usage of immunomodulatory drugs, such as dexamethasone, with promising results in severe COVID-19 patients to reduce mortality. However, there is a need to consider the inherent genetic factors of an individual that may influence the dexamethasone drug's metabolism and action. To understand this, there is a need to evaluate the genes involved in the pharmacokinetics and pharmacodynamic pathways of the drug and study the effects of the drug. This will aid in choosing the right individuals who will benefit from the therapy. Hence, the present review summarized the reported genetic variations that impact dexamethasone drug response. Immunomodulatory and analgesic effects of dexamethasone are clinically well established, and this synthetic corticosteroid acts as an agonist of glucocorticoid receptors. Early results of the RECOVERY Trial from the United Kingdom and others suggest certain benefits of dexamethasone against COVID-19 chronic patients. The efforts have been acknowledged by World Health Organization with an interim guideline to use in patients with a severe and critical illness. The inherent genetic variations in genes such as CYP3A5, NR3C1, NR3C2, etc., involved in the pharmacokinetic and pharmacodynamic processes may influence dexamethasone's effects as an anti-inflammatory drug. Besides, the drug may influence transcriptome or metabolic changes in the individuals. In the present review, we summarize the reported genetic variations that impact dexamethasone response and discuss dexamethasone-induced changes in transcriptome and metabolome that may influence potential treatment outcome against COVID-19.