Ivermectin for preventing and treating COVID‐19

Background Ivermectin, an antiparasitic agent used to treat parasitic infestations, inhibits the replication of viruses in vitro. The molecular hypothesis of ivermectin's antiviral mode of action suggests an inhibitory effect on severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) replication in the early stages of infection. Currently, evidence on efficacy and safety of ivermectin for prevention of SARS‐CoV‐2 infection and COVID‐19 treatment is conflicting. Objectives To assess the efficacy and safety of ivermectin compared to no treatment, standard of care, placebo, or any other proven intervention for people with COVID‐19 receiving treatment as inpatients or outpatients, and for prevention of an infection with SARS‐CoV‐2 (postexposure prophylaxis). Search methods We searched the Cochrane COVID‐19 Study Register, Web of Science (Emerging Citation Index and Science Citation Index), medRxiv, and Research Square, identifying completed and ongoing studies without language restrictions to 26 May 2021. Selection criteria We included randomized controlled trials (RCTs) comparing ivermectin to no treatment, standard of care, placebo, or another proven intervention for treatment of people with confirmed COVID‐19 diagnosis, irrespective of disease severity, treated in inpatient or outpatient settings, and for prevention of SARS‐CoV‐2 infection. Co‐interventions had to be the same in both study arms. We excluded studies comparing ivermectin to other pharmacological interventions with unproven efficacy. Data collection and analysis We assessed RCTs for bias, using the Cochrane risk of bias 2 tool. The primary analysis excluded studies with high risk of bias. We used GRADE to rate the certainty of evidence for the following outcomes 1. to treat inpatients with moderate‐to‐severe COVID‐19: mortality, clinical worsening or improvement, adverse events, quality of life, duration of hospitalization, and viral clearance; 2. to treat outpatients with mild COVID‐19: mortality, clinical worsening or improvement, admission to hospital, adverse events, quality of life, and viral clearance; (3) to prevent SARS‐CoV‐2 infection: SARS‐CoV‐2 infection, development of COVID‐19 symptoms, adverse events, mortality, admission to hospital, and quality of life. Main results We found 14 studies with 1678 participants investigating ivermectin compared to no treatment, placebo, or standard of care. No study compared ivermectin to an intervention with proven efficacy. There were nine