Invermectin is an antiparasitic drug being investigated for repurposing to SARS-CoV-2. In-vitro, ivermectin showed limited antiviral activity and a COVID-19 animal model demonstrated pathological benefits but no effect on viral RNA. This meta-analysis investigated ivermectin in 18 randomized clinical trials (2282 patients) identified through systematic searches of PUBMED, EMBASE, MedRxiv and trial registries. Ivermectin was associated with reduced inflammatory markers (C-Reactive Protein, d-dimer and ferritin) and faster viral clearance by PCR. Viral clearance was treatment dose- and duration-dependent. In six randomized trials of moderate or severe infection, there was a 75% reduction in mortality (Relative Risk=0.25 [95%CI 0.12-0.52]; p=0.0002); 14/650 (2.1%) deaths on ivermectin; 57/597 (9.5%) deaths in controls) with favorable clinical recovery and reduced hospitalization. Many studies included were not peer reviewed and meta-analyses are prone to confounding issues. Ivermectin should be validated in larger, appropriately controlled randomized trials before the results are sufficient for review by regulatory authorities.
