June 23, 2021

expert reaction to PRINCIPLE trial to investigate whether ivermectin is an effective COVID-19 treatment for recovery at home and in other non-hospital settings

It has been announced that Ivermectin, a safe, broad spectrum antiparasitic drug, is to be investigated as a possible treatment for COVID-19 in Oxford’s PRINCIPLE trial.

Dr Stephen Griffin, Associate Professor in the School of Medicine, University of Leeds, said:

“The inclusion of Ivermectin on the PRINCIPLE trial should provide a final answer to the questions over whether this drug might be repurposed as an antiviral targeting SARS-CoV2.  Much like hydroxychloroquine (HCQ) before, there has been a considerable amount of off-label use of this drug, based primarily upon in vitro cell culture data.  However, antiviral effects have only been demonstrated in such systems at concentrations much higher than those corresponding to routine anti-parasitic treatment.  This is an important consideration and reason for caution as one of the appealing aspects of this drug is its widespread use and safety record which are naturally at standard doses.  It is hard to accurately judge the fidelity of this drug versus the virus as multiple mechanisms of action have been suggested, many of which act against host cell processes.

“There are numerous studies and meta analyses supporting the use of Ivermectin for COVID therapy, yet there are no supportive RCTs and many other small studies showing no benefit, including a recent paper in the Lancet.  The danger with such off-label use is that, much like HCQ, the use of the drug becomes driven by specific interest group or proponents of non-conventional treatments and becomes politicised.  In this respect, a well conducted RCT would be welcome to resolve ongoing controversy, although one must question whether such resource is justified by available supporting data.  Of note, Merck, the manufacturer of this drug, categorically states that it is not recommended for COVID therapy and the WHO have stipulated that it should not be used outside of a trial setting.”

https://www.principletrial.org/news/ivermectin-to-be-investigated-as-a-possible-treatment-for-covid-19-in-oxford2019s-principle-trial

Declared interests

Dr Stephen Griffin: “No conflicts.”