Melatonin in the Prophylaxis of SARS-CoV-2 Infection in Healthcare Workers (MeCOVID): A Randomised Clinical Trial

• Published in: Journal of clinical medicine Vol. 11; no. 4; p. 1139
• Main Authors: García-García, Irene, Seco-Meseguer, Enrique, Ruiz-Seco, Pilar, Navarro-Jimenez, Gema, Martínez-Porqueras, Raúl, Espinosa-Díaz, María, Ortega-Albás, Juan José, Sagastagoitia, Iñigo, García-Morales, María Teresa, Jiménez-González, María, Martínez de Soto, Lucía, Bajo-Martínez, Ana Isabel, Del Palacio-Tamarit, María, López-García, Raquel, Díaz-García, Lucía, Queiruga-Parada, Javier, Giesen, Christine, Pérez-Villena, Ana, de Castro-Martínez, Marta, González-García, Juan J, Rodriguez-Rubio, Miguel, de la Oliva, Pedro, Arribas, José R, Carcas, Antonio J, Borobia, Alberto M
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 21-02-2022; MDPI
• Subjects: Asymptomatic; Clinical trials; Coronaviruses; COVID-19; Disease prevention; Hospitals; Infections; Informed consent; Medical personnel; Melatonin; Pandemics; Polymerase chain reaction; Population; Severe acute respiratory syndrome coronavirus 2; Software; Statistical analysis; Variables; Viral infections; Vital signs; Madrid Spain; Spain; COVID-19; SARS-CoV-2; melatonin; prophylaxis; healthcare workers
• ISSN: 2077-0383; 2077-0383
• DOI: 10.3390/jcm11041139

We evaluated in this randomised, double-blind clinical trial the efficacy of melatonin as a prophylactic treatment for prevention of SARS-CoV-2 infection among healthcare workers at high risk of SARS-CoV-2 exposure. Healthcare workers fulfilling inclusion criteria were recruited in five hospitals in Spain and were randomised 1:1 to receive melatonin 2 mg administered orally for 12 weeks or placebo. The main outcome was the number of SARS-CoV-2 infections. A total of 344 volunteers were screened, and 314 were randomised: 151 to placebo and 163 to melatonin; 308 received the study treatment (148 placebo; 160 melatonin). We detected 13 SARS-CoV-2 infections, 2.6% in the placebo arm and 5.5% in the melatonin arm (
= 0.200). A total of 294 adverse events were detected in 127 participants (139 in placebo; 155 in melatonin). We found a statistically significant difference in the incidence of adverse events related to treatment: 43 in the placebo arm and 67 in the melatonin arm (
= 0.040), and in the number of participants suffering from somnolence related to treatment: 8.8% (
= 14) in the melatonin versus 1.4% (
= 2) in the placebo arm (
= 0.008). No severe adverse events related to treatment were reported. We cannot confirm our hypothesis that administration of melatonin prevents the development of SARS-CoV-2 infection in healthcare workers.