Efficacy of single-dose and double-dose ivermectin early treatment in preventing progression to hospitalization in mild COVID-19: A multi-arm, parallel-group randomized, double-blind, placebo-controlled trial

Background and objective: Ivermectin is a known anti-parasitic agent that has been investigated as an antiviral agent against coronavirus disease 2019 (COVID-19). This study aimed to evaluate the efficacy of ivermectin in mild COVID-19 patients.

Methods: In this multi-arm randomized clinical trial conducted between 9 April 2021 and 20 May 2021, a total of 393 patients with reverse transcription-PCR-confirmed COVID-19 infection and mild symptoms were enrolled. Subjects were randomized in a 1:1:1 ratio to receive single-dose ivermectin (12 mg), double-dose ivermectin (24 mg) or placebo. The primary outcome was need for hospitalization.

Results: There was no significant difference in the proportion of subjects who required hospitalization between the placebo and single-dose ivermectin groups (absolute difference in the proportions: -2.3 [95% CI = -8.5, 4.1]) and between the placebo and double-dose ivermectin groups (absolute difference in the proportions: -3.9 [95% CI = -9.8, 2.2]). The odds of differences in mean change in severity score between single-dose ivermectin and placebo groups (OR_difference = 1.005 [95% CI: 0.972, 1.040]; p = 0.762) and double-dose ivermectin and placebo groups (OR_difference = 1.010 [95% CI: 0.974, 1.046]; p = 0.598) were not statistically significant. None of the six adverse events (including mild dermatitis, tachycardia and hypertension) were serious and required extra action.

Conclusion: Single-dose and double-dose ivermectin early treatment were not superior to the placebo in preventing progression to hospitalization and improving clinical course in mild COVID-19.