- Although some small studies have shown encouraging results on ivermectin for Covid-19, rigorous scientific data is still lacking
- A new study tested the effectiveness of the drug in reducing the duration of symptoms in mild Covid-19, but it was found not to make any significant difference
- The researchers, however, say that larger trials should be conducted
As the debate on the use of ivermectin for Covid-19 rages on among medical practitioners and the general public, results of a new clinical trial showed that a five-day course of the parasitic drug didn’t significantly improve the time of recovery among adults with mild infection.
The researchers, whose study was published in JAMA, wrote that their findings don't support the use of ivermectin for treatment of mild Covid infection, although larger trials may be needed to understand whether the drug can provide benefits against other classifications, such as severe disease and hospitalisation.
Reason for the study
“Because of evidence of activity against SARS-CoV-2 in vitro [in the laboratory] and in animal models, ivermectin has attracted interest in the global scientific community and among policymakers,” the study authors wrote.
“Several countries have included ivermectin in their treatment guidelines, leading to a surge in the demand for the medication by the general population and even alleged distribution of veterinary formulations. However, clinical trials are needed to determine the effects of ivermectin on Covid-19 in the clinical setting.”
Based on the results of past experimental studies on ivermectin having antiviral activity, the researchers hypothesised that the drug would accelerate recovery in patients with Covid when administered during the first days of infection.
About the study
The randomised controlled trial was carried out at a site in Cali, Colombia, and observed 476 healthy individuals with mild disease and symptoms for seven days or fewer (at home or hospitalised – but not receiving high-flow nasal oxygen or mechanical ventilation).
The most common symptoms they experienced were myalgia and headache, followed by loss of smell and taste, as well as cough. They were enrolled in the study between July and November 2020, and were followed up through December. All participants were identified through the state’s health department electronic database of patients with symptomatic, laboratory-confirmed Covid-19 during the study period.
They were then randomised to receive an oral dose of ivermectin (300 micrograms/kg of body weight per day for five days) or a placebo (a substance with no therapeutic benefit).
Headache was common among 104 (52%) participants who received ivermectin, and among 111 (56%) participants who received the placebo. Multiorgan failure, a serious adverse event, occurred in four participants (two in each group).
Resolution of symptoms
The average time it took for symptoms to resolve was 10 days in the ivermectin group, compared with 12 days in the placebo group, the study authors wrote. By day 21, 82% of the ivermectin group and 79% of the placebo group had completely resolved symptoms, they added.
According to Johns Hopkins Medicine, those with a mild case of Covid generally recovered within one to two weeks. Based on this, and the time it took for symptoms to resolve in study participants, the authors concluded:
“Among adults with mild Covid-19, a 5-day course of ivermectin, compared with placebo, did not significantly improve the time to resolution of symptoms. The findings do not support the use of ivermectin for treatment of mild Covid-19, although larger trials may be needed to understand the effects of ivermectin on other clinically relevant outcomes.”
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