Ivermectin Therapy Not Efficacious in Patients With Mild COVID-19

Ivermectin, 3 mg tablet, as sold in the USA. Brand name: Stromectol, manufactured by Edenbridge Pharmaceuticals. It is also sold under brand names Heartgard and Sklice. Ivermectin is a broad-spectrum antiparasitic agent, traditionally against parasitic worms. It is mainly used in humans in the treatment of onchocerciasis (river blindness), but is also effective against other worm infestations (such as strongyloidiasis, ascariasis, trichuriasis, filariasis and enterobiasis), and some epidermal parasitic skin diseases, including scabies. From Wikipedia: Ivermectin is currently being used to help eliminate river blindness (onchocerciasis) in the Americas, and to stop transmission of lymphatic filariasis and onchocerciasis around the world in programs sponsored by the Carter Center using ivermectin donated by Merck. The disease is endemic in 30 African countries, six Latin American countries, and Yemen, according to studies conducted by the World Health Organization. The drug rapidly kills microfilariae, but not the adult worms. A single oral dose of ivermectin, taken annually for the 10- to 15-year lifespan of the adult worms, is all that is needed to protect the individual from onchocerciasis.
Investigators selected patients with mild COVID-19 to receive either ivermectin or placebo to determine whether ivermectin is an efficacious treatment.

Compared to placebo, ivermectin did not significantly improve time to symptom resolution in mild COVID-19 cases, according to results from a double-blind, randomized trial (ClinicalTrials.gov: NCT04405843) published in JAMA.

Mild COVID-19 patients with a median age of 37 years (interquartile range [IQR], 29-48) were randomly assigned to receive either ivermectin or placebo at 300 μg/kg per day for 5 days. In the primary analysis, a total of 200 patients were allocated to ivermectin and 198 patients to placebo. The median time to symptom resolution in patients was 10 days for ivermectin and 12 for placebo (difference, -2 days; IQR, -4 to 2). The hazard ratio [HR] for resolution of symptoms was 1.07 (95% CI, 0.87-1.32; P =.53).

Overall, symptoms were resolved in 82% of patients in the ivermectin group and 79% of patients in the placebo group. Clinical deterioration of symptoms by 2 or more points occurred in 2% and 3.5% of patients in the ivermectin and placebo groups, respectively, and was not statistically significant. There was also no significant difference in the proportion of patients needing an escalation of care between groups.

A total of 154 patients (77%) in the ivermectin group and 161 patients (81.3%) in the placebo group reported adverse events. Of these, 15 patients (7.5%) in the ivermectin group and 5 patients (2.5%) in the placebo group discontinued treatment. Headache, which occurred in 52% of ivermectin patients and 56% of placebo patients, was the most commonly reported adverse event. The most common serious adverse event was multiorgan failure, which only occurred in 2 patients in the ivermectin group and 2 patients in the placebo group.

The original primary outcome of detecting the ability of ivermectin to prevent clinical deterioration was changed 6 weeks into the trial as the incidence of deterioration was low. The study was also limited by lack of power to detect a smaller reduction in primary endpoint, lack of virological assessments, alternative placebos used in 65 patients, a reliance on self-reporting for 2 secondary outcomes, and lack of data on ivermectin plasma levels.

According to investigators, the findings do not support ivermectin as a treatment for mild COVID19. However, investigators did acknowledge that larger trials are needed to fully understand the effects of ivermectin on other clinically relevant outcomes.

Disclosure: Several study authors declared affiliations with the pharmaceutical industry. Please see the original reference for a full list of authors’ disclosures.


López-Medina E, López P, Hurtado IC, et al. Effect of ivermectin on time to resolution of symptoms among adults with mild COVID-19 a randomized clinical trial. JAMA. Published online March 4, 2021. doi:10.1001/jama.2021.3071

This article originally appeared on Infectious Disease Advisor