The antiparasitic ivermectin failed to treat COVID-19 in yet another randomized clinical trial, but the drug remains popular amid the pandemic thanks to Republican politics. That’s the takeaways from two separate studies published Friday in JAMA Internal Medicine.
Together, the studies raise even more concerns about ivermectin’s use against the pandemic virus — as well as the reasons behind its use, which appear to be politically motivated.
“Political preference should not be a factor in clinical treatment decisions,” concluded the Harvard researchers behind one of the studies. “Our findings raise concerns about public confidence in an impartial health care system.”
political influence
The study began when researchers led by Harvard health policy researcher Michael Barnett noted the surge in prescriptions for ivermectin during the pandemic, despite evidence that the drug is ineffective in treating COVID-19. The researchers looked at whether prescription levels could be associated with state-level political voting patterns in the 2020 U.S. presidential election. For comparison, they also looked at prescribing patterns for another antiparasitic drug called albendazole, as well as the immunosuppressive drug methotrexate.
Barnett and colleagues reviewed medical claims from more than 18.5 million adults to assess prescribing practices in U.S. counties from January 2019 to December 2020. They then sorted the counties into four groups based on their share of the Republican vote, with the first quartile having the lowest share of the Republican vote and the fourth having the highest
Total ivermectin prescribing increased 964 percent in December 2020 compared to prepandemic prescription levels in 2019. But those December 2020 prescriptions weren’t evenly distributed; the counties with the highest shares of Republican votes had the highest prescription levels of ivermectin. In fact, the higher the proportion of Republican votes in a county, the higher the level of ivermectin prescribing.
The authors saw a similar pattern with hydroxychloroquine after the Food and Drug Administration revoked an emergency use authorization for use against COVID-19 in March 2020. highest share of Republican votes. Meanwhile, there were no such politically connected trends or changes in prescription levels for the two control drugs, methotrexate and albendazole.
“Our findings are consistent with the hypothesis that prescribing hydroxychloroquine and ivermectin in the US during the COVID-19 pandemic may have been influenced by political affiliation,” Barnett and colleagues concluded. The findings add context to the continued use of ivermectin for COVID-19, even as evidence continues to grow that the drug is ineffective and potentially dangerous.
Failed Trial
In addition to Barnett’s study, researchers in Malaysia reported results from a randomized clinical trial involving 490 high-risk COVID-19 patients. In the study, ivermectin failed to prevent COVID-19 from developing into serious disease in these high-risk patients. It also made no statistically significant difference in a variety of COVID-19 outcomes, including timing of disease progression, length of hospital stay, need for mechanical ventilation, need for intensive care, and death.
In Malaysia, people are required to report cases of COVID-19 to authorities and those at risk of disease progression are either referred to hospital or admitted to a COVID-19 quarantine center. That all made it easier to closely monitor trial participants. The study enrolled people who were COVID-19 positive, were 50 years of age or older, and had at least one underlying medical condition. At the time of enrollment, the 490 patients were considered to have mild to moderate infections. From there, 241 were randomly assigned to receive oral ivermectin for five days, and 249 were randomly assigned to receive standard care.
At the end of the study, 52 of 241 patients receiving ivermectin (21.6 percent) had progressed to severe disease, while 43 of 249 patients just receiving standard care (17.3 percent) had progressed. While there were no significant differences in other disease outcomes, the researchers documented more side effects in the ivermectin group.
A total of 44 patients reported adverse events, 33 of which were in the ivermectin group. Diarrhea was the most common side effect that ivermectin is known to cause. There were also five cases of serious adverse events, four of which were in the ivermectin group. Two patients in the ivermectin group had heart attacks, one had severe anemia and one developed hypovolemic shock due to severe diarrhea. The only serious reaction remaining in the control group was abdominal bleeding.
Not the first time
While some early clinical work had suggested ivermectin may be effective for treating COVID-19, experts have since noted methodological flaws in those studies. In addition, the findings in the Malaysia trial echo two other randomized clinical trials, in Colombia and Argentina. These studies also found no benefit to using ivermectin to improve COVID-19 symptoms or reduce hospitalization rates.
Overall, the authors of the Malaysian study conclude that, in their “randomized clinical trial of high-risk patients with mild to moderate COVID-19, treatment with ivermectin during early disease did not prevent progression to severe disease. The study results support the use of ivermectin for patients with COVID-19.”
