IVERMECTIN
Recently, there has been some activity on the web concerning the possibility that another anti-malarial drug may show some promise for fighting COVID-19. As with Hydroxychloroquine, this drug, Ivermectin has been around for a long time and its use has been relatively safe with mostly minor side effects.
Ivermectin was developed to treat parasitic diseases and was first approved for use with head lice. It is primarily used as a treatment for River Fever, a parasitic worm infection, and has several veterinary uses.
Recall that HCQ was originally targeted because it had some anti-viral activity when used in a laboratory flask with cells challenged by older coronaviruses, but that the activity observed at that time was insufficient to merit increased study, animal trials or human trials. Nevertheless, the minimally positive results have led to an increased scrutiny of HCQ for treating COVID-19.
Those potential indications have triggered a group of researchers in Australia to look at the invitro (tissue grown in the lab in a flask) effects of Ivermectin to inhibit viral growth. There has been some indication in other invitro studies with other viruses that the drug may have some ability to reduce infection in the lab.
There was a Phase 3 clinical trial of Ivermectin in Thailand between 2014 and 2017 looking to see if the laboratory anti-viral effects could fight Dengue Virus infection. The results of those large-scale trials showed that the drug was safe at the levels used and that although it reduced the amount of one of the viral proteins observed in the blood, it did not result in any change in viral infection and did not show any clinical benefit.
I do not want to go into the potential mechanism of action of this drug, but leave it to say that it is different from HCQ and primarily works on the cellular membranes of parasites as opposed to HCQ which may work on the protein synthesis in human cells after viral infection. The impetus for study here is rather that there is some empirical evidence that this drug can have anti-viral activity when studied in the lab.
BOTTOM LINE
This study is a very, very preliminary study and provides little if any pharmaco-medical information on treating COVID-19.
The biggest problem with the study has to do with drug dosing. The general approved safe level of this drug is about 15 mg. per day for an average adult male, and the dosing is approved at a safe level of 3 consecutive days.
The experimenters in this study challenged human tissue culture cells with virus and Ivermectin simultaneously at drug levels that were literally hundreds of times higher than any dosage that has been used in humans. They then found that there was a greater than 95% reduction in the production of virus within 48 hours when compared to a control.
Not only does this suggest that a dosage in humans would have to be hugely greater than any safety/efficacy trial has ever studied, but to achieve the concentrations of drug in the blood at potential points of infection in the lungs, those dosages would have to be even orders of magnitude greater.
This study, very preliminarily suggests that there may be reason to do further research on this drug or perhaps on analogues, but it DOES NOT suggest that the drug should be used in any clinical setting at this time, particularly if that use were to replace treatments that have either shown efficacy or delay or replace clinical trials on more promising treatments.
THE FDA WARNING
On April 10 the FDA’s Center for Veterinary Medicine issued a warning on this drug.
In part here is what they have said:
“(referring to this article) This type of study is commonly used in the early stages of drug development. Ivermectin was not given to people or animals in this study. Additional testing is needed to determine whether ivermectin might be safe or effective to prevent or treat coronavirus or COVID-19.
FDA is concerned about the health of consumers who may self-medicate by taking ivermectin products intended for animals, thinking they can be a substitute for ivermectin intended for humans. People should never take animal drugs, as the FDA has only evaluated their safety and effectiveness in the particular animal species for which they are labeled. These animal drugs can cause serious harm in people. People should not take any form of ivermectin unless it has been prescribed to them by a licensed health care provider and is obtained through a legitimate source.
The FDA has established a cross-agency task force dedicated to closely monitoring for fraudulent COVID-19 products that reaches out to major retailers to ask for their help in monitoring online marketplaces. Products that claim to prevent, diagnose, treat, or cure COVID-19 are subject to FDA investigation and potential enforcement action if they have not demonstrated safety and effectiveness for that intended use. The task force has already worked with retailers to remove dozens of these types of product listings online.”