In December 2019 outbreak of cases of Pneumonia of unknown etiology were identified in Wuhan city in Hubei province of China. By 7th January 2020 the Chinese authorities identified a new strain of coronavirus which was later named as 2019 novel coronavirus (2019-nCoV). By 30th January 2020, the World Health Organization (WHO) declared the outbreak as Public Health Emergency of International Concern. Since then the cases of viral pneumonia associated with this strain have gripped almost all countries of the world.  WHO subsequently declared COVID19 as pandemic on 11th March 2020. As per WHO data, as on 17th April 2020 the overall cases worldwide are 2,074529 with 139,378 deaths attributed to this viral illness. Countries like US, Spain, Italy and France are having the maximum burden of this illness.

There is no efficacious treatment for the disease till date. Proposed drugs with potential efficacy can be broadly categorised into 4 classes, i.e., (a) Anti-viral  and  Anti-inflammatory drugs,  (b)  Anti-malaria  drugs,  (c) Traditional  Chinese  drugs  (TCM)  and  (d)  other treatments/drugs.    Small clinical trials have demonstrated the effect of hydroxychloroquine on viral clearance.(4) However, there are reports of cardiotoxicity and lack of benefit in severe disease.  As of today, hydroxychloroquine with or without azithromycin is not being recommended by any of the major international societies or national guidelines for treatment.  Ritonavir-lopinavir did not achieve its primary endpoint in a recently published randomized controlled trial, even though it did reduce duration of mechanical ventilation and other secondary outcomes. Similarly, there are encouraging reports with use of remdesivir, but there are concerns regarding patient selection in its use.  Other experimental therapies like plasma exchange, convalescent plasma and interferon therapy are being studied.

We postulate that single dose ivermectin given early in the course of infection, will result in decreased viral load, that will translate into lesser number of days that a patient remains infective, which will, in turn, reduce basic reproduction number (R0) for COVID19.  Also, as high viral load has been correlated with complications in later course, there is potential to reduce progression to severe disease and complications.  Another interesting aspect is that ivermectin is best suited to mass treatment in suspected COVID19 cases, as it has been tried in mass prophylaxis programs in other diseases like leishmaniasis. As it is in essential drug list, if found useful, its use would also be cost effective.

We have performed a pharmacokinetic modelling study, and based on available pharmacokinetic data, and virucidal concentrations used in the in-vitro study, we have calculated that the required dose of ivermectin for achieving the peak plasma level, and also the area under curve for majority of elimination half-life, is 96 mg (1600 mg/kg), with an estimated half-life of around 60 hours (personal observation, submitted for publication). However, a dose ranging study in COVID patients is important to decide regarding safe and effective dose.