Effect of ivermectin on COVID-19: A multicenter double-blind randomized controlled clinical trial

Purpose : Given the coronavirus disease-2019 (COVID-19) pandemic, there is a global urgency to discover an effective treatment against this disease. This study aimed to evaluate the effect of the widely used antiparasitic drug ivermectin on COVID-19 patient outcomes. Methods In this randomized double-blind clinical trial, COVID-19 patients admitted to two referral tertiary hospitals of Mazandaran, north of Iran, were randomly divided into two groups of intervention and control. In addition to standard treatment for COVID-19, the intervention group received a single weight-based dose (0.2 mg/kg) of ivermectin. Demographic, clinical, laboratory and imaging data of participants were recorded at baseline. Patients were daily assessed for clinical complaints and disease progression. The primary clinical outcome measures were duration of hospital stay, fever, dyspnea, cough, and overall clinical improvement. Findings : Sixty-nine patients with the mean age of 47.6±22.2 and 45.2±23.1 years participated in intervention and control groups, respectively (p=0.6). Nineteen patients (54%) in the ivermectin group and 18(53%) in control group were male (p=0.9). The mean duration of dyspnea was 2.4±1.7 days in the ivermectin and 3.7±2.1 days in the control group (p=0.02). Also, persistent cough lasted for 3.1±1.9 days in the ivermectin group compared to 4.8±2.0 days in control group (p=0.00). The mean duration of hospital stay was 6.9±3.1 vs 8.3±3.3 days for the ivermectin and control group, respectively (p=0.01). Also, the frequency of lymphopenia decreased to 14.3% in the ivermectin group and did not change in the control group (p=0.00). Implications A single dose of ivermectin was well-tolerated in symptomatic COVID-19 patients and improved important clinical features of COVID-19 patients including dyspnea, cough, and lymphopenia. Further studies with larger sample sizes, different drug dosages, dosing intervals and durations, especially in different stages of the disease, may help understanding ivermectin's potential clinical benefits. Trial registration The current controlled trial was registered in the Iranian Registry of Clinical Trials (code: IRCT20111224008507N3) on 2020-06-27.