LIVERPOOL, England — Ivermectin, a drug used to treat parasitic infections in humans as well as some livestock, has been flying off the shelves of animal feed stores and pharmacies around the country. This comes amid reports that it can fight COVID-19 and prevent death in patients. While some scientists say the drug could be a major weapon during the coronavirus pandemic, a new review shows that there simply is not enough “quality” evidence to support such claims.
Scientists from the Liverpool School of Tropical Medicine (LSTM) worked with researchers from the COVID-19 Evidence Ecosystem to lead the extensive review. They used data from 13 studies in which a combined 1,374 COVID-19 patients were either treated with ivermectin, a placebo, or no treatment beyond typical standards of care. Another study of 304 individuals investigated whether or not ivermectin could prevent COVID-19 infections.
The authors sought to conclude whether patients’ conditions improved or worsened, whether the drug caused harmful side effects, if a patient’s risk of death was reduced, and if it could prevent infection.
An analysis published earlier this summer led scientists to conclude that ivermectin could not only help treat COVID-19 patients, but it might even be powerful enough to end the pandemic entirely. But the researchers behind this latest review are slamming the brakes on those conclusions. They say that these small randomized, controlled trials are simply not reliable enough to reach any valid conclusions.
“The lack of good quality evidence on efficacy and safety of ivermectin arises from a study pool that consists mainly of small, insufficiently powered RCTs with overall limited quality regarding study design, conduct and reporting. Current evidence does not support using ivermectin for treating or preventing of COVID-19 unless they are part of well-designed randomized trials,” say study co-authors Drs. Maria Popp and Stephanie Weibel, in a statement.
After reviewing these studies, the research team says they cannot conclude that ivermectin can prevent COVID-19. Nor can they declare that it successfully treats infected patients, or prevents them from dying. There is also not enough evidence to show that the drug would worsen a patient’s condition or raise their risk of death.
“This is a great review from an experienced team. The hype around ivermectin is driven by some studies where the effect size for ivermectin is frankly not credible, and this has driven the conclusions in other reviews,” notes Paul Garner, a professor at LSTM and director of the Cochrane Infectious Disease Group. “The study with a huge effect has now been retracted as fake. Careful appraisal is the cornerstone of Cochrane’s work, and with such extreme public demands for a drug to work during the pandemic, it remains vital that we hold onto our scientific principles to guide care.”
Findings are published in the Cochrane Database of Systematic Reviews.