Repurposing drugs for COVID-19
Not every attempt at repurposing a drug works as hoped, however.
At the start of the pandemic, scientists and doctors tried to find
inexpensive medications to repurpose for the treatment and prevention of COVID-19. Chloroquine and hydroxychloroquine were two of those drugs. They were chosen because of possible antiviral effects documented in
laboratory studies and limited
anecdotal case reports from the first COVID-19 outbreaks in China. However,
large clinical studies of these drugs to treat COVID-19 did not translate to any meaningful benefits. This was partly due to the
serious toxic effects patients experienced before the drugs reached a high enough dose to inhibit or kill the virus.
Unfortunately,
lessons from these failed attempts have not been applied to ivermectin. The false hope around using ivermectin to treat COVID-19 originated from an
April 2020 laboratory study in Australia. Although the results from this study were
widely circulated,
I immediately had serious doubts. The concentration of ivermectin they tested was 20 to 2,000 times higher than the standard dosages used to treat human parasitic infections. Indeed, many other pharmaceutical experts
confirmed my
initial concerns within a month of the paper’s publication. Such high concentrations of the drug could be significantly toxic.
Another commonly cited paper on ivermectin’s purported effects against COVID-19 was withdrawn in July 2021 after scientists found serious flaws with the study. These flaws ranged from incorrect statistical analyses to discrepancies between collected data and published results to duplicated patient records and the inclusion of study subjects who died before even entering the study. Even more concerning, at least two other oft-cited studies have raised significant concerns about scientific fraud.
At the time of this writing, two large randomized clinical trials both showed no significant benefit from the use of ivermectin for COVID-19. Reputable national and international health care organizations, including the
World Health Organization, the
Centers for Disease Control and Prevention, the
National Institutes of Health, the
Food and Drug Administration and the
Infectious Diseases Society of America, unanimously recommend against the use of ivermectin to prevent or treat COVID-19 unless in the context of a clinical trial.
Consequences of using ivermectin for COVID-19
Unfortunately, many
organizations with dubious intentions have continued to promote unsubstantiated use of invermectin for COVID-19. This has led to a dramatic rise in
ivermectin prescriptions and a
flood of calls to U.S. poison control centers for
ivermectin overdoses. Many calls were due to ingestion of large amounts of veterinary products containing ivermectin – two
deaths linked to ivermectin overdose were reported in September 2021.
Ivermectin, when used correctly, has prevented millions of potentially fatal and debilitating infectious diseases. It’s meant to be prescribed only to treat infections caused by parasites. It’s not meant to be prescribed by parasites looking to
extract money from
desperate people during a pandemic. It’s my sincere hope that this unfortunate and tragic chapter in the otherwise incredible story of a lifesaving medication will come to a quick end.
Written by Jeffrey R. Aeschlimann, Associate Professor of Pharmacy, University of Connecticut.