Inhaled route and anti-inflammatory action of ivermectin: Do they hold promise in fighting against COVID-19?

In an effort to curb the global pandemic due to coronavirus, the scientific community is exploring various treatment strategies with a special emphasis on drug repurposing. Ivermectin, an anti-helminthic drug is also being proposed for treatment and prevention of COVID-19. Ivermectin has demonstrated broad spectrum antiviral activity against both DNA and RNA viruses. Due to its potential to interfere with transport of SARS-CoV-2 nucleocapsid protein to nucleus, it is being proposed to have antiviral activity against this virus as well which has been confirmed in an in-vitro study. However, in-vitro to in-vivo extrapolation studies indicate an inability to achieve the desired IC50 levels of ivermectin after oral administration of doses up to 10 times higher than the approved anti-helminthic dose. In a modelling simulation study, drug accumulation in the lungs was noticed at levels having potential antiviral activity. It is hypothesised that inhaled formulation of ivermectin may be effective against SARS-CoV-2. Therefore, ivermectin administered via inhalational route needs to be explored for potential beneficial role in COVID-19 in preclinical and clinical studies. We also hypothesise the possibility of drug having anti-inflammatory action in coronavirus associated severe respiratory illness based on few in-vitro and in-vivo reports which however needs to be confirmed clinically.