Utilizing drug repurposing against COVID-19 – Efficacy, limitations, and challenges

Abstract

The recent outbreak of Coronavirus disease (COVID-19), first in Eastern Asia and then essentially across the world has been declared a pandemic by the WHO. COVID-19 is caused by a novel virus SARS-CoV2 (2019-nCoV), against which there is currently no vaccine available; and current antiviral therapies have failed, causing a very high mortality rate. Drug repurposing i.e. utilizing an approved drug for different indication, offers a time- and cost-efficient alternative for making new therapies available to patients. Although there are several reports presenting novel approaches to treat COVID-19, still an attentive review of previous scientific literature is essential to overcome their failure to exhibit efficacy. There is an urgent need to provide a comprehensive outlook toward utilizing drug repurposing as a tool for discovery of new therapies against COVID-19. In this article, we aim to provide a to-the-point review of current literature regarding efficacy of repurposed drugs against COVID-19 and other respiratory infections caused by coronaviruses. We have briefly discussed COVID-19 epidemiology, and then have discussed drug repurposing approaches and examples, specific to respiratory viruses. Limitations of utilization of repurposed drug molecules such as dosage regimen and associated challenges such as localized delivery in respiratory tract have also been discussed in detail.

Current understanding of the impact of COVID-19 on gastrointestinal disease: Challenges and openings

“…Tocilizumab has been linked to HBV reactivation and thus HBV serology should be part of the routine pre-treatment workup. The lack of clinical data suggesting a specific benefit of these agents do not explain their risks[ 53 , 117 ].…”

Pineal hormone melatonin as an adjuvant treatment for COVID‑19 (Review)

“…Pharmaceutical research is focused on the investigation of novel drugs; however, this is time consuming, due to drug resistance and repeatedly occurring virus mutations ( 56 - 58 ). Furthermore, antiviral drugs are effective in mild to moderate cases of the virus, if used in early stages; however, they are not able to treat patients who have severe symptoms, due to overreaction of the innate immune response, which leads to destructive inflammation ( 59 , 60 ). To overcome the complexity of viral infection, a symptomatic and non-virus-specific therapy should be considered ( 61 ).…”

Therapeutic Potential of Inhalable Medications to Combat Coronavirus disease-2019

“…In addition, extensive investigations are underway into repurposing drugs which are already approved for a specific indication, for treating respiratory viral infections [ 4 ]. For instance, many US FDA-approved and investigational antiviral drugs used in the past against SARS and Middle East Respiratory Syndrome (MERS) (either alone or in combination), are now being investigated for their efficacy against COVID-19 [ 5 ].…”